vxa2scsi  1009566
VXA-2 SCSI Reference
COPYRIGHT
Copyright 2002 - 2008 by Tandberg Data Corporation. All rights reserved. This item and
the information contained herein are the property of Tandberg Data Corporation. No
part of this document may be reproduced, transmitted, transcribed, stored in a retrieval
system, or translated into any language or computer language in any form or by any means,
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express written permission of Tandberg Data Corporation, 2108 55th Street, Boulder,
Colorado 80301.
DISCLAIMER
Tandberg Data Corporation makes no representation or warranties with respect to the
contents of this document and specifically disclaims any implied warranties of
merchantability or fitness for any particular purpose. Further, Tandberg Data
Corporation reserves the right to revise this publication without obligation of Tandberg
Data Corporation to notify any person or organization of such revision or changes.
TRADEMARK
NOTICES
Tandberg Data Corporation trademarks: Tandberg Data, Exabyte, the Exabyte logo,
EZ17, M2, VXA, and VXAtape are registered trademarks; ExaBotics, MammothTape,
and SmartClean are trademarks; SupportSuite is a service mark.
Other trademarks: All other product names are trademarks or registered trademarks of
their respective owners.
PART NUMBER
1009566-001 Revision E
REVISION HISTORY
Revision Date
Description
000
001
C
D
April 2002
December 2003
May 2006
August 2007
E
October 2008
Initial release
Error codes updated.
Update error codes.
1-Added Drive Statistics Page 3C to LOG SENSE
command
2-Add Byte 4, Bits 2 and 1 to MODE SELECT/ MODE
SENSE Vendor Unique Parameters);
3-Add compression note to READ/WRITE BUFFER;
4-Add Bytes 32–45 in REQ SEN (What TD returns);
5-Add ASC 30h/ASCQ 03h/FSC 07h to Error codes
6-Converted from Exabyte to Tandberg Data.
Updated Request Sense Data information.
NOTE: The most current information about this product is available at Tandberg Data’s web
site (www.tandbergdata.com).
CONTACTING
TANDBERG DATA
CORPORATION
ii
SCSI REFERENCE
To obtain general information
World Wide Web
Refer to the Tandberg Data website
(www.tandbergdata.com) for current address and
contact information.
1009566-001
Contents
About This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4
4
xiii
Contents of This Manual . . . . . . . . . . . . . . . . . 4-xiii
Conventions Used in This Manual . . . . . . . . . . 4-xiii
Related Publications . . . . . . . . . . . . . . . . . . . . 4-xiv
1 SCSI Command Protocol Overview . . . . . . . . . . . . . . 1-1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
Communication Interface Versus Command Protocol . . . .
Supported SCSI Commands. . . . . . . . . . . . . . . . . . . . . . . .
SCSI Command Descriptor Block Format. . . . . . . . . . . . . .
Field Definitions for the Command Descriptor Block . . . . .
1.4.1
Field Definitions for Six-Byte CDBs . . . . . . . . . .
1.4.2
Field Definitions for Ten-Byte CDBs . . . . . . . . .
Command Format Errors . . . . . . . . . . . . . . . . . . . . . . . . . .
Command Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.6.1
Good . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.6.2
Check Condition . . . . . . . . . . . . . . . . . . . . . . . .
1.6.3
Busy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.6.4
Reservation Conflict . . . . . . . . . . . . . . . . . . . . .
Converting an Existing VXA-1 Driver . . . . . . . . . . . . . . . .
1-1
1-2
1-4
1-5
1-5
1-6
1-7
1-8
1-8
1-8
1-9
1-9
1-10
2 Implementing Tape Drive Operations . . . . . . . . . . . . 2-1
2.1
2.2
2.3
2.4
2.5
2.6
2.7
OCTOBER 2008
Data Cartridges for the VXA-2 Tape Drive . . . . . . . . . . . . .
2.1.1
Loading a Data Cartridge. . . . . . . . . . . . . . . . . .
2.1.2
Unloading a Data Cartridge. . . . . . . . . . . . . . . .
Using Data Compression . . . . . . . . . . . . . . . . . . . . . . . . . .
Setting the Size of Logical Blocks . . . . . . . . . . . . . . . . . . . .
Using Filemarks and Setmarks . . . . . . . . . . . . . . . . . . . . . .
Maximizing Data Transfer Efficiency . . . . . . . . . . . . . . . . .
Formatting and Using Partitioned Tapes. . . . . . . . . . . . . . .
2.6.1
Creating a Partitioned Tape . . . . . . . . . . . . . . . .
2.6.2
Using a Multi-Partition Tape . . . . . . . . . . . . . . .
Handling Unit Attention Conditions. . . . . . . . . . . . . . . . . .
VXA-2 TAPE DRIVE
2-1
2-2
2-2
2-3
2-3
2-4
2-4
2-5
2-6
2-7
2-9
iii
2.8
2.7.1
Effect of Changing Data Cartridges . . . . . . . . . .
2.7.2
Clearing the Unit Attention Condition. . . . . . . .
Resetting the Tape Drive . . . . . . . . . . . . . . . . . . . . . . . . . .
2.8.1
Effect of Power-on Reset. . . . . . . . . . . . . . . . . .
2.8.2
Effect of SCSI Bus and Device Resets . . . . . . . .
2.8.3
Reset Processing . . . . . . . . . . . . . . . . . . . . . . . .
2-10
2-10
2-11
2-11
2-12
2-12
3 ERASE (19h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
3.1
3.2
3.3
3.4
About This Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CDB Field Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tape Positioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exceptions and Error Conditions . . . . . . . . . . . . . . . . . . . . .
3-1
3-2
3-3
3-3
4 INQUIRY (12h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
4.1
4.2
4.3
4.4
About This Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
CDB Field Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
What the Tape Drive Returns . . . . . . . . . . . . . . . . . . . . . . . 4-2
4.3.1
Standard Inquiry Data. . . . . . . . . . . . . . . . . . . . . 4-3
4.3.2
Supported Vital Product Data Page
(Page Code 00h). . . . . . . . . . . . . . . . . . . . . . . . . 4-6
4.3.3
Unit Serial Number Page (Page Code 80h) . . . . . 4-8
4.3.4
Device Identification Page (Page Code 83h) . . . . 4-9
4.3.5
Original Inquiry Data Page (Page Code C0h). . . 4-10
Exceptions and Error Conditions . . . . . . . . . . . . . . . . . . . . 4-11
5 LOAD/UNLOAD (1Bh) . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
5.1
5.2
5.3
About This Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
CDB Field Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2
Exceptions and Error Conditions . . . . . . . . . . . . . . . . . . . . . 5-4
6 LOCATE (2Bh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
6.1
6.2
6.3
6.4
About This Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using the LOCATE Command. . . . . . . . . . . . . . . . . . . . . . .
CDB Field Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exceptions and Error Conditions . . . . . . . . . . . . . . . . . . . . .
6-1
6-1
6-2
6-3
7 LOG SELECT (4Ch) . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1
7.1
7.2
7.3
7.4
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SCSI REFERENCE
About This Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CDB Field Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Log Parameter Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7.3.1
Parameter List Header . . . . . . . . . . . . . . . . . . . .
7.3.2
Log Parameters . . . . . . . . . . . . . . . . . . . . . . . . . .
Exceptions and Error Conditions . . . . . . . . . . . . . . . . . . . . .
7-1
7-2
7-4
7-4
7-5
7-8
1009566-001
8 LOG SENSE (4Dh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1
8.1
8.2
8.3
8.4
About This Command . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CDB Field Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . .
What the Tape Drive Returns . . . . . . . . . . . . . . . . . . . . . .
8.3.1
Log Parameter Format . . . . . . . . . . . . . . . . . . . .
8.3.2
Supported Log Pages Page (Page Code 00h) . . .
8.3.3
Write Error Counters Page (Page Code 02h)
Read Error Counters Page (Page Code 03h) . . . .
8.3.4
TapeAlert Page (Page Code 2Eh) . . . . . . . . . . . .
8.3.5
Compression Statistics (Page Code 30h). . . . . .
8.3.6
Tape Capacity Page (Page Code 31h) . . . . . . .
8.3.7
Environmental Counter Page (Page Code 36h)
8.3.8
Tape Usage Page (Page Code 37h) . . . . . . . . .
8.3.9
Tape Last FSC Page (Page Code 39h). . . . . . . .
8.3.10
Drive Statistics Page (Page Code 3Ch) . . . . . . .
Exceptions and Error Conditions . . . . . . . . . . . . . . . . . . .
8-1
8-2
8-4
8-5
8-8
8-8
8-9
8-12
8-13
8-13
8-14
8-16
8-18
8-20
9 MODE SELECT (15h). . . . . . . . . . . . . . . . . . . . . . . . . . 9-1
9.1
9.2
9.3
About This Command . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CDB Field Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mode Parameter Data . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.3.1
Parameter List Header. . . . . . . . . . . . . . . . . . . .
9.3.2
Block Descriptor . . . . . . . . . . . . . . . . . . . . . . . .
9.4 Read-Write Error Recovery Page (Page Code 01h) . . . . . . .
9.5 Disconnect-Reconnect Page (Page Code 02h) . . . . . . . . . .
9.6 Control Mode Page (Page Code 0Ah). . . . . . . . . . . . . . . . .
9.7 Data Compression Page (Page Code 0Fh) . . . . . . . . . . . .
9.8 Device Configuration Page (Page Code 10h) . . . . . . . . . .
9.9 Medium Partition Page (Page Code 11h) . . . . . . . . . . . . .
9.10 TapeAlert Page (Page Code 1Ch) . . . . . . . . . . . . . . . . . . .
9.11 Vendor Unique Parameters Page 1 (Page Code 21h) . . . .
9.12 Exceptions and Error Conditions . . . . . . . . . . . . . . . . . . .
9-1
9-1
9-3
9-3
9-4
9-6
9-7
9-9
9-11
9-13
9-16
9-22
9-24
9-28
10 MODE SENSE (1Ah) . . . . . . . . . . . . . . . . . . . . . . . . . 10-1
10.1 About This Command . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1
10.2 CDB Field Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1
10.3 What the Tape Drive Returns . . . . . . . . . . . . . . . . . . . . . 10-3
10.3.1
Block Descriptor . . . . . . . . . . . . . . . . . . . . . . . 10-5
10.3.2
Read-Write Error Recovery Page (Page Code 01h) . . .
10-6
10.3.3
Disconnect-Reconnect Page (Page Code 02h) . 10-7
10.3.4
Control Mode Page (Page Code 0Ah) . . . . . . . 10-9
OCTOBER 2008
VXA-2 TAPE DRIVE
v
10.3.5
10.3.6
10.3.7
10.3.8
10.3.9
Data Compression Page (Page Code 0Fh) . . . . 10-11
Device Configuration Page (Page Code 10h) . . 10-12
Medium Partition Page (Page Code 11h). . . . . 10-16
TapeAlert Page (Page Code 1Ch) . . . . . . . . . . 10-17
Vendor Unique Parameters Page 1 (Page Code 21h).
10-20
10.3.10 Vendor Unique Parameters Page 2 (Page Code 22h).
10-24
10.4 Exceptions and Error Conditions . . . . . . . . . . . . . . . . . . . 10-25
11 PREVENT/ALLOW MEDIUM REMOVAL (1Eh) . . . . . . 11-1
11.1 About This Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-1
11.2 CDB Field Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-2
12 READ (08h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-1
12.1 About This Command . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12.2 CDB Field Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12.3 Exceptions and Error Conditions . . . . . . . . . . . . . . . . . . . .
12.3.1
Transfer Length Incorrect . . . . . . . . . . . . . . . . .
12.3.2
Additional Errors. . . . . . . . . . . . . . . . . . . . . . . .
12-1
12-1
12-3
12-3
12-6
13 READ BLOCK LIMITS (05h) . . . . . . . . . . . . . . . . . . . . 13-1
13.1 About This Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-1
13.2 CDB Field Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-1
13.3 What the Tape Drive Returns . . . . . . . . . . . . . . . . . . . . . . 13-2
14 READ BUFFER (3Ch) . . . . . . . . . . . . . . . . . . . . . . . . . 14-1
14.1 About This Command . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14.2 CDB Field Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14.3 What the Tape Drive Returns . . . . . . . . . . . . . . . . . . . . . .
14.3.1
Buffer Descriptor . . . . . . . . . . . . . . . . . . . . . . .
14.4 Exceptions and Error Conditions . . . . . . . . . . . . . . . . . . . .
14-1
14-2
14-3
14-3
14-4
15 READ POSITION (34h) . . . . . . . . . . . . . . . . . . . . . . . 15-1
15.1
15.2
15.3
15.4
About This Command . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CDB Field Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . .
What the Tape Drive Returns . . . . . . . . . . . . . . . . . . . . . .
Exceptions and Error Conditions . . . . . . . . . . . . . . . . . . . .
15-1
15-1
15-2
15-4
16 RECEIVE DIAGNOSTIC RESULTS (1Ch). . . . . . . . . . . 16-1
16.1 About This Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-1
16.2 CDB Field Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-1
16.3 What the Tape Drive Returns . . . . . . . . . . . . . . . . . . . . . . 16-2
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SCSI REFERENCE
1009566-001
16.3.1
16.3.2
16.3.3
Supported Diagnostic Pages Page (Page Code 00h) . .
16-3
Self Test Page (Page Code F0h) . . . . . . . . . . . . 16-3
No Diagnostic Results Available Page
(Page Code FFh) . . . . . . . . . . . . . . . . . . . . . . . 16-4
17 RELEASE UNIT (17h) . . . . . . . . . . . . . . . . . . . . . . . . . 17-1
17.1 About This Command . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-1
17.2 CDB Field Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-1
18 REQUEST SENSE (03h) . . . . . . . . . . . . . . . . . . . . . . . 18-1
18.1
18.2
18.3
18.4
About This Command . . . . . . . . . . . . . . . . . . . . . . . . . . .
CDB Field Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . .
What the Tape Drive Returns . . . . . . . . . . . . . . . . . . . . .
Sense Byte Pending Status . . . . . . . . . . . . . . . . . . . . . . .
18-1
18-1
18-2
18-10
19 RESERVE UNIT (16h). . . . . . . . . . . . . . . . . . . . . . . . . 19-1
19.1 About This Command . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-1
19.2 CDB Field Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-1
19.3 Exceptions and Error Conditions . . . . . . . . . . . . . . . . . . . 19-2
20 REWIND (01h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-1
20.1 About This Command . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-1
20.2 CDB Field Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-2
20.3 Exceptions and Error Conditions . . . . . . . . . . . . . . . . . . . 20-2
21 SEND DIAGNOSTIC (1Dh) . . . . . . . . . . . . . . . . . . . . 21-1
21.1 About This Command . . . . . . . . . . . . . . . . . . . . . . . . . . . 21-1
21.2 CDB Field Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . 21-2
21.3 Additional Diagnostic Data . . . . . . . . . . . . . . . . . . . . . . . 21-3
21.3.1
Supported Diagnostic Pages Page (Page Code 00h) . .
21-4
21.3.2
Self Test Page (Page Code F0h) . . . . . . . . . . . . 21-4
22 SPACE (11h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22-1
22.1 About This Command . . . . . . . . . . . . . . . . . . . . . . . . . . . 22-1
22.2 CDB Field Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . 22-2
22.3 Exceptions and Error Conditions . . . . . . . . . . . . . . . . . . . 22-3
23 TEST UNIT READY (00h). . . . . . . . . . . . . . . . . . . . . . 23-1
23.1 About This Command . . . . . . . . . . . . . . . . . . . . . . . . . . . 23-1
23.2 CDB Field Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . 23-1
23.3 Exceptions and Error Conditions . . . . . . . . . . . . . . . . . . . 23-2
OCTOBER 2008
VXA-2 TAPE DRIVE
vii
24 WRITE (0Ah) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24-1
24.1 About This Command . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24.1.1
Tape Positioning . . . . . . . . . . . . . . . . . . . . . . . .
24.1.2
Data Buffering . . . . . . . . . . . . . . . . . . . . . . . . .
24.2 CDB Field Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24.3 Exceptions and Error Conditions . . . . . . . . . . . . . . . . . . . .
24-1
24-1
24-2
24-3
24-3
25 WRITE BUFFER (3Bh) . . . . . . . . . . . . . . . . . . . . . . . . 25-1
25.1 About This Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25-1
25.1.1
Cautions for Using the WRITE BUFFER Command . .
25-2
25.1.2
Aborting a Write Buffer Operation . . . . . . . . . . 25-2
25.2 CDB Field Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25-2
25.3 Updating the Tape Drive Microcode . . . . . . . . . . . . . . . . . 25-3
25.4 Exceptions and Error Conditions . . . . . . . . . . . . . . . . . . . . 25-5
26 WRITE FILEMARKS (10h) . . . . . . . . . . . . . . . . . . . . . . 26-1
26.1 About This Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26-1
26.2 CDB Field Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26-2
26.3 Exceptions and Error Conditions . . . . . . . . . . . . . . . . . . . . 26-3
A Error Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1
A.1
A.2
REQUEST SENSE Information . . . . . . . . . . . . . . . . . . . . . . . A-1
Error Recovery Procedures . . . . . . . . . . . . . . . . . . . . . . . . A-11
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-1
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SCSI REFERENCE
1009566-001
Tables
1 SCSI Command Protocol Overview
Table 1-1
Table 1-2
Table 1-3
Supported SCSI commands . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Definition of the Status Byte code . . . . . . . . . . . . . . . . . . . . . 1-8
Converting an existing VXA-1 device driver to a VXA-2 device
driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10
2 Implementing Tape Drive Operations
Table 2-1
VXAtape cartridge capacities in gigabytes (GB) . . . . . . . . . . . . 2-1
3 ERASE (19h)
Table 3-1
REQUEST SENSE data for ERASE command errors and exceptions .
3-3
4 INQUIRY (12h)
Table 4-1
Table 4-2
CDB values for different types of Inquiry data . . . . . . . . . . . . 4-2
REQUEST SENSE data for INQUIRY command errors and
exceptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11
5 LOAD/UNLOAD (1Bh)
Table 5-1
Table 5-2
Action occurring based on the Load bit and data cartridge status . .
5-3
REQUEST SENSE data for LOAD/UNLOAD command errors and
exceptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4
6 LOCATE (2Bh)
Table 6-1
REQUEST SENSE data for LOCATE command errors and exceptions
6-3
7 LOG SELECT (4Ch)
Table 7-1
Table 7-2
OCTOBER 2008
Valid values for the LOG SELECT Page Control (PC) field . . . . 7-2
Page length of each supported log page . . . . . . . . . . . . . . . . . 7-3
VXA-2TAPE DRIVE
ix
Table 7-3
Table 7-4
Table 7-5
Table 7-6
Table 7-7
Valid combinations of values for the fields in the LOG SELECT CDB
7-3
Page length of each supported log page . . . . . . . . . . . . . . . . . 7-5
Parameter Codes and default values for the Write Error and Read
Error Counters pages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6
Valid values for the LOG SELECT Threshold Met Criteria (TMC)
field . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-7
REQUEST SENSE data for LOG SELECT command errors and
exceptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-8
8 LOG SENSE (4Dh)
Table 8-1
Table 8-2
Table 8-3
Table 8-4
Table 8-5
Table 8-6
Table 8-7
Table 8-8
Table 8-9
Table 8-10
Table 8-11
Table 8-12
Table 8-13
Valid values for the LOG SENSE Page Control (PC) field . . . . . 8-2
Log pages supported by the tape drive . . . . . . . . . . . . . . . . . . 8-3
Minimum Allocation Length required for each supported log page .
8-4
Valid values for the LOG SENSE Threshold Met Criteria (TMC) field
8-7
Parameters returned on the LOG SENSE Write Error and Read Error
Counters pages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-9
Parameters returned on the LOG SENSE TapeAlert page . . . . 8-11
Parameters returned on the LOG SENSE Compression Statistics
page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-12
Parameters returned on the LOG SENSE Tape Capacity page 8-13
Parameters returned on the LOG SENSE Environmental Counter
page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-14
Parameters returned on the LOG SENSE Tape Usage page . . 8-15
Parameters returned on the LOG SENSE Tape Last FSC page 8-17
Parameters returned on the LOG SENSE Drive Statistics page 8-18
REQUEST SENSE data for LOG SENSE command errors and
exceptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-20
9 MODE SELECT (15h)
Table 9-1
Table 9-2
Table 9-3
Table 9-4
Table 9-5
Table 9-6
Table 9-7
Table 9-8
x
SCSI REFERENCE
MODE SELECT parameter page lengths . . . . . . . . . . . . . . . . . 9-2
Values for the Density Code field in the MODE SELECT command.
9-5
Valid values for the MODE SELECT DTDC field . . . . . . . . . . . 9-9
Partition characteristics resulting from the combinations of the FDP,
SDP, and IDP bits in the Medium Partition page . . . . . . . . . . 9-20
Valid values for MRIE in the MODE SELECT command. . . . . 9-23
Test Flag Number settings for MODE SELECT . . . . . . . . . . . . 9-24
Valid values for RespDuringImmed in the MODE SELECT
command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-27
REQUEST SENSE data for MODE SELECT command errors and
exceptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-28
1009566-001
10 MODE SENSE (1Ah)
Table 10-1
Table 10-2
Table 10-3
Table 10-4
Table 10-5
Table 10-6
Table 10-7
Table 10-8
Table 10-9
Valid values for the PC field in the MODE SENSE command. 10-2
Valid values for the Page Code field in the MODE SENSE
command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-2
Values returned for Medium Type field in MODE SENSE data 10-4
Values for the Density Code field in the MODE SENSE command .
10-5
Values returned in the MODE SENSE DTDC field. . . . . . . . . 10-9
Valid values for MRIE in the MODE SELECT command. . . . 10-19
Test Flag Number settings for MODE SENSE . . . . . . . . . . . . 10-20
Valid values for RespDuringImmed in the MODE SENSE command
10-23
REQUEST SENSE data for MODE SENSE command errors and
exceptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-25
11 PREVENT/ALLOW MEDIUM REMOVAL (1Eh)
12 READ (08h)
Table 12-1
REQUEST SENSE data for READ command errors and exceptions .
12-6
13 READ BLOCK LIMITS (05h)
14 READ BUFFER (3Ch)
Table 14-1
Table 14-2
Valid Mode settings for the READ BUFFER command . . . . . . 14-2
REQUEST SENSE data for READ BUFFER command errors and
exceptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-4
15 READ POSITION (34h)
Table 15-1
REQUEST SENSE data for READ POSITION command errors and
exceptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-4
16 RECEIVE DIAGNOSTIC RESULTS (1Ch)
Table 16-1
Maximum page length of each supported RECEIVE DIAGNOSTIC
page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-2
17 RELEASE UNIT (17h)
18 REQUEST SENSE (03h)
Table 18-1
OCTOBER 2008
Sense Key values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-4
VXA-2 TAPE DRIVE
xi
19 RESERVE UNIT (16h)
20 REWIND (01h)
Table 20-1
REQUEST SENSE data for REWIND command errors and
exceptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-2
21 SEND DIAGNOSTIC (1Dh)
Table 21-1
Maximum page length of each supported SEND DIAGNOSTIC
page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21-3
22 SPACE (11h)
Table 22-1
Table 22-2
Valid values for the Code field in the SPACE (11h) CDB . . . . 22-2
REQUEST SENSE data for SPACE command errors and exceptions .
22-6
23 TEST UNIT READY (00h)
Table 23-1
REQUEST SENSE data for TEST UNIT READY command errors and
exceptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23-2
24 WRITE (0Ah)
Table 24-1
REQUEST SENSE data for WRITE command errors and exceptions.
24-5
25 WRITE BUFFER (3Bh)
Table 25-1
Table 25-2
Valid Mode settings for the WRITE BUFFER (3Bh) command 25-2
REQUEST SENSE data for WRITE BUFFER command errors and
exceptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25-5
26 WRITE FILEMARKS (10h)
Table 26-1
REQUEST SENSE data for WRITE FILEMARKS command errors and
exceptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26-4
A Error Codes
Table A-1
Table A-2
xii
SCSI REFERENCE
ASC, ASCQ, FSC, and Sense Key data returned by the REQUEST
SENSE command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2
Recommended error recovery procedures . . . . . . . . . . . . . . A-11
1009566-001
ABOUT THIS MANUAL
This manual provides reference information for developing software to
support applications for the VXA-2™ tape drive by Tandberg Data
Corporation.
CONTENTS OF THIS MANUAL
This manual contains the following information:
Chapter 1 provides an overview of how the VXA-2 tape drive implements
the Small Computer System Interface (SCSI). It also provides information
about adapting device drivers developed for the VXA-1 tape drive for use
with the VXA-2 tape drive.
Chapter 2 provides background information and instructions for
implementing common tape drive operations in your application.
Chapter 3 through Chapter 26 describe the SCSI commands supported by
the tape drive. To help you find the information you need quickly, the SCSI
commands are listed in alphabetic order.
Appendix A lists the possible combinations of values for the Additional
Sense Code (ASC) and Additional Sense Code Qualifier (ASCQ) fields
returned by the REQUEST SENSE (03h) command for each sense key. It also
lists the Fault Symptom Codes (FSCs) that may be returned by the
REQUEST SENSE command and recommends error recovery procedures
(ERPs) for each Fault Symptom Code.
CONVENTIONS USED IN THIS MANUAL
This manual uses the following conventions to highlight important
information:
Note: Notes provide additional information or suggestions about the topic or
procedure being discussed.
!
Caution
OCTOBER 2008
Important
Read information marked by the “Important” icon for
information that will help you complete a procedure or avoid
extra steps.
Read the information marked by the “CAUTION” icon for information you must
know to avoid damaging the tape drive or losing data.
VXA-2 TAPE DRIVE
xiii
RELATED PUBLICATIONS
This manual provides information about the SCSI command protocol and the
parallel SCSI bus communication interface used by the VXA-2 tape drive. The
following publications provide additional, related information.
VXA-2 Tape Drive
VXA-3, VXA-172, or VXA2 Tape Drive Quick Start Guide, 1017485
VXA-2 Tape Drive Product Manual, 1009541
Standards
The following standards are related to the SCSI command protocol and
parallel SCSI bus communication interface used by the tape drive.
ANSI Small Computer System Interface-2 (SCSI-2), X3.131 – 1994
ANSI SCSI Parallel Interface-2 (SPI-2), X3T10/1142D, Rev. 11
ANSI Information Technology SCSI Primary Commands-2 (SPC-2), T10/1236-D,
Revision 18
ANSI Information Technology SCSI Primary Commands-2 (SPC-2), T10/1236-D,
Revision 19
TapeAlert Specification, Version 2.0, November, 1997
xiv
SCSI REFERENCE
1009566-001
1
SCSI COMMAND PROTOCOL
OVERVIEW
This chapter provides an overview of how the Small Computer System
Interface (SCSI) command protocol is implemented for the VXA-2 tape drive.
It discusses the following topics:
Communication interface versus command protocol
SCSI commands supported by the tape drive
Format of the SCSI command descriptor blocks
Command status supported by the tape drive
Converting an existing VXA-1 driver
1.1
COMMUNICATION INTERFACE VERSUS COMMAND PROTOCOL
When two devices are connected across a bus or a network, their interaction is
accomplished through a communication interface (for example, a parallel SCSI
bus, a Fibre Channel arbitrated loop, or an Ethernet network). The
communication interface allows multiple devices to share connections, yet
operate and exchange data independently. The communication interface is
comprised of the physical interface and the signaling protocol used during
communication.
The physical interface determines the number of devices that can be attached
to a bus or network loop, the maximum length of the cables, and the physical
characteristics of the cable itself (for example, the number of wires, shielding,
and so forth). The signaling protocol defines the electrical characteristics and
timing of signals carried by the cable, the message system requirements,
transmission speeds and maximum data transfer rates, as well as the encoding
and decoding of the individual bit patterns representing commands passing
between the individual devices.
OCTOBER 2008
VXA-2 TAPE DRIVE
1-1
CHAPTER 1 SCSI COMMAND PROTOCOL OVERVIEW
The format and content of the information carried over the communication
interface, as well as how each device uses and responds to the information, is
governed by a command protocol. The command protocol determines how the
host (or initiator) interacts with the target device (for example, the tape drive)
by issuing commands, transferring data, and responding to status
information. The command protocol also defines the individual bits in the
command data passing between the individual devices. The target device
responds to commands from the host by performing the requested operation
(for example, writing or reading data on magnetic tape) and returning status
information to the host.
1.2
SUPPORTED SCSI COMMANDS
The tape drive supports the SCSI commands shown in Table 1-1.
Table 1-1 Supported SCSI commands
Command
Operation
code (hex)
What the tape drive does
in response to this command
Described
in...
19h
Erases the tape starting from the current legal position to the
physical end of tape (PEOT). Rewinds the tape when finished.
Chapter 3
12h
Provides the initiator with information about the tape drive’s
device parameters, including product and vendor
identification.
Chapter 4
1Bh
Loads or unloads a data cartridge. When loading a cartridge,
the tape drive places the tape in the tape path and positions it
at the logical beginning of partition (LBOP) or the logical
beginning of the default partition. When unloading a data
cartridge, the tape drive writes any buffered information to the
tape, rewinds the tape to the physical beginning of the tape
(PBOT), removes the tape from the tape path, and ejects the
data cartridge (unless ejection has been prevented by a
PREVENT/ALLOW MEDIUM REMOVAL command).
Chapter 5
2Bh
Positions the tape at a specified logical position. (Typically, this
position is determined by data that was obtained through a
previous READ POSITION command.)
Chapter 6
4Ch
Manages a set of internal counters regarding read and write
error recovery operations and amounts of data compressed.
The initiator can set threshold and cumulative values for the
counters or reset the counters.
Chapter 7
LOG
SENSE
4Dh
Returns the values of the counters managed by the LOG
SELECT command.
Chapter 8
MODE
SELECT
15h
Changes the tape drive’s internal medium, logical unit, or
device parameters to values specified by the initiator.
Chapter 9
MODE
SENSE
1Ah
Provides the initiator with information about the tape drive’s
internal medium, logical unit, and device parameters.
Chapter 10
ERASE
INQUIRY
LOAD/
UNLOAD
LOCATE
LOG
SELECT
1-2
SCSI REFERENCE
1009566-001
1.2 SUPPORTED SCSI COMMANDS
Table 1-1 Supported SCSI commands (continued)
Command
Operation
code (hex)
What the tape drive does
in response to this command
Described
in...
Prevents or allows the removal of the data cartridge from the
tape drive. When the PREVENT MEDIUM REMOVAL
Chapter 11
command is in effect, the tape drive's eject button is disabled.
PREVENT/
ALLOW
MEDIUM
REMOVAL
1Eh
READ
08h
Transfers data from the tape to the initiator.
Chapter 12
05h
Provides the initiator with information about the maximum
and minimum logical block lengths that the tape drive can
support for read and write operations in the current operating
mode.
Chapter 13
3Ch
Creates a diagnostic listing of the tape drive's current state or
the contents of the tape drive’s data buffer.
Chapter 14
34h
Reports the current logical position of the tape to the initiator.
This allows the initiator to store the position for later use in
locating data with a LOCATE command.
Chapter 15
READ
BLOCK
LIMITS
READ
BUFFER
READ
POSITION
Reports the results of diagnostic tests to the initiator.
RECEIVE
DIAGNOSTIC
RESULTS
1Ch
RELEASE
UNIT
17h
Releases the tape drive from exclusive use by the initiator that
had previously reserved it with a RESERVE UNIT command.
Chapter 17
REQUEST
SENSE
03h
Provides the initiator with sense information describing a
condition that just occurred.
Chapter 18
RESERVE
UNIT
16h
Reserves the tape drive for exclusive use by the initiator that
issued the command or for a third party.
Chapter 19
01h
Rewinds the tape to the logical beginning of the tape (LBOT)
or the logical beginning of the current partition.
Chapter 20
1Dh
Performs diagnostic functions specified by the initiator. (For
the initiator to receive the results of the tests, this command
must be followed by a RECEIVE DIAGNOSTIC RESULTS
command.)
Chapter 21
11h
Searches forward or backward on the tape a specified number
Chapter 22
of logical blocks, filemarks, or setmarks.
TEST
UNIT READY
00h
Indicates whether the tape drive is ready to accept a medium
Chapter 23
access command (such as READ or WRITE) from the initiator.
WRITE
0Ah
Accepts data from the initiator to be written to the tape.
Chapter 24
WRITE
BUFFER
3Bh
Transfers new microcode from the initiator into the tape
drive’s control memory.
Chapter 25
10h
Writes any data remaining in the tape drive’s buffer to the
tape, then writes a specified type and number of filemarks or
setmarks following the data.
Chapter 26
REWIND
SEND
DIAGNOSTIC
SPACE
WRITE
FILEMARKS
OCTOBER 2008
Chapter 16
VXA-2 TAPE DRIVE
1-3
CHAPTER 1 SCSI COMMAND PROTOCOL OVERVIEW
1.3
SCSI COMMAND DESCRIPTOR BLOCK FORMAT
The following sections describe the general formats for the six- and ten-byte
command descriptor blocks (CDBs) used by the tape drive, the format of the
Operation Code, and the typical format for the Control byte. The formats for
the six- and ten-byte CDBs are implemented according to the ANSI Small
Computer System Interface 2 (SCSI-2) standard.
The word Reserved or RSVD has one of the following meanings when used in a
SCSI command field definition:
The field is defined as reserved by the ANSI Small Computer System Interface
(SCSI-2) standard. The tape drive checks these fields for a value of 0. If zeros
are not present, the tape drive returns Check Condition status with the
sense key set to Illegal Request (5h).
The field has not been defined in the Tandberg Data implementation of the
command. These fields are reserved for future enhancements. The tape
drive ignores these fields and does not check for illegal values.
CDB FOR SIX-BYTE COMMANDS
Bit
Byte
7
6
4
3
2
Logical Unit Number
01
0
Command Dependent
(MSB)
Logical Block Address
03
(LSB)
04
Control Byte
05
1-4
1
Operation Code
00
02
5
SCSI REFERENCE
1009566-001
1.4 FIELD DEFINITIONS FOR THE COMMAND DESCRIPTOR BLOCK
CDB FOR TEN-BYTE COMMANDS
Bit
Byte
7
6
5
4
3
2
1
0
Operation Code
00
Logical Unit Number
01
Command Dependent
(MSB)
02
…
Logical Block Address
(LSB)
05
Reserved
06
(MSB)
07
Transfer, Parameter List, or Allocation Length
08
(LSB)
Control Byte
09
FORMAT OF THE OPERATION CODE
Bit
Byte
7
6
5
4
3
Group Code
00
2
1
0
1
0
Flag
Link
Command Code
TYPICAL FORMAT OF THE CONTROL BYTE
Bit
Byte
6
5
4
Vendor Unique
nn
1.4
7
3
2
Reserved
FIELD DEFINITIONS FOR THE COMMAND DESCRIPTOR BLOCK
The following sections provide field definitions for the six- and ten-byte
command descriptor blocks (CDB).
1.4.1
FIELD DEFINITIONS FOR SIX-BYTE CDBS
Byte 00 – Operation Code
The Operation Code consists of two subfields, the Group Code and the
Command Code, which are defined as follows:
Bits 7 through 5 – Group Code The Group Codes supported by the tape
drive are defined by the specific command.
Bits 4 through 0 – Command Code The Command Codes supported by the
tape drive are defined by the specific command.
OCTOBER 2008
VXA-2 TAPE DRIVE
1-5
CHAPTER 1 SCSI COMMAND PROTOCOL OVERVIEW
Byte 01, Bits 7 through 5 – Logical Unit Number (LUN)
The LUN designates a specific unit within a group of devices associated with
the target. Since the tape drive is a single device target and does not support
multiple devices, the LUN must be 0 for all commands.
Byte 01, Bits 4 through 0 – Command Dependent
These bits are used as defined in the specific commands.
Bytes 02 through 04 – Logical Block Address
These bytes are used as defined in the specific commands.
Byte 05 – Control Byte
The Control Byte field consists for four subfields, which are defined as follows:
Bits 7 and 6 – Vendor Unique The VXA-2 tape drive does not use the
vendor-unique information bits. The value for this field must be 0.
Bits 5 through 2 – Reserved
The value for this field must be 0.
Bit 1 – Flag The tape drive does not recognize the Flag bit. The value for this
field must be 0.
Bit 0 – Link The tape drive does not support linked commands. The value for
this field must be 0.
1.4.2
FIELD DEFINITIONS FOR TEN-BYTE CDBS
Byte 00 – Operation Code
The Operation Code consists of two subfields, the Group Code and the
Command Code, which are defined as follows:
Bits 7 through 5 – Group Code The Group Codes supported by the tape
drive are defined by the specific command.
Bits 4 through 0 – Command Code The Command Codes supported by the
tape drive are defined by the specific command.
Byte 01, Bits 7 through 5 – Logical Unit Number (LUN)
The LUN designates a specific unit within a group of devices associated with
the target. Since the tape drive is a single device target and does not support
multiple devices, the LUN must be 0 for all commands.
Byte 01, Bits 4 through 0 – Command Dependent
These bits are used as defined in the specific commands.
Bytes 02 through 05 – Logical Block Address
These bits are used as defined in the specific commands.
1-6
SCSI REFERENCE
1009566-001
1.5 COMMAND FORMAT ERRORS
Byte 06 – Reserved
The value for this field must be 0.
Bytes 07 and 08 – Transfer, Parameter List, or Allocation Length
These bytes contain the transfer length, the parameter list length, or the
allocation length as required by the specific command.
Byte 09 – Control Byte
The Control Byte field consists for four subfields, which are defined as follows:
Bits 7 and 6 – Vendor Unique The VXA-2 tape drive does use the
vendor-unique information bits. The value for this field must be 0.
Bits 5 through 2 – Reserved
The value for this field must be 0.
Bit 1 – Flag The tape drive does not recognize the Flag bit. The value for this
field must be 0.
Bit 0 – Link The tape drive does not support linked commands. The value for
this field must be 0.
1.5
COMMAND FORMAT ERRORS
A command format error may occur when:
The Operation Code in the CDB is not supported by the tape drive.
The Logical Unit Number (LUN) in the CDB is not 0.
The value of the bytes or bits in a Reserved field (as defined by the ANSI
SCSI-2 standard) is not 0.
The value of the Link or Flag fields in the Control byte (bits 1 and 0) of the
CDB are not 0, or the value of the Vendor Unique fields (bits 7 and 6) are not
valid as defined for the specific command.
For all command format errors, the tape drive terminates the command and
returns Check Condition status to the initiator. The sense data is set as follows:
The sense key is set to Illegal Request (5h).
Depending on the specific error, the Additional Sense Code (ASC) is set to
Illegal Operation Code (20h), Logical Unit Not Supported (25h), or Invalid
Field in CDB (24h).
The Additional Sense Code Qualifier (ASCQ) is set to 0.
The sense key specific data indicates the location of the error.
OCTOBER 2008
VXA-2 TAPE DRIVE
1-7
CHAPTER 1 SCSI COMMAND PROTOCOL OVERVIEW
1.6
COMMAND STATUS
The tape drive sends one status byte to the initiator at the completion of a
command. The status byte is formatted as follows:
Bit
Byte
7
6
5
4
Reserved
00
3
2
1
0
Status Byte Code
Table 1-2 lists the meanings of the Status Byte Codes supported by the tape
drive. Note that the value of bit 0 is always 0. The following sections provide
more detailed explanations of the status bytes and the reasons they are sent.
Table 1-2 Definition of the Status Byte code
Bit
Hex
value
5
4
3
2
1
0
00h
0
0
0
0
0
0
Good. Indicates that the tape drive successfully completed
the command.
02h
0
0
0
0
1
0
Check Condition. Indicates any error, exception, or
abnormal condition that causes sense information to be set.
Meaning
08h
0
0
1
0
0
0
Busy. Indicates that the tape drive is busy. This status is sent
whenever the tape drive is unable to accept a command from
an initiator.
18h
0
1
1
0
0
0
Reservation Conflict. Indicates that the tape drive is reserved
for the exclusive use of another initiator.
1.6.1
GOOD
Good status indicates that the operation specified by the CDB completed
normally. For those commands that support the immediate return of status,
Good status indicates that the tape drive has accepted the command and will
attempt to perform the operation specified by the CDB. If the specified
operation does not complete normally, Check Condition status will be
reported to the initiator when the next command is received by the tape drive
from the same initiator.
1.6.2
CHECK CONDITION
The tape drive returns Check Condition status to indicate that a situation
occurred during the execution of a command that should be checked by the
initiator. Check Condition status does not necessarily mean that the command
has failed to complete successfully.
The reporting of Check Condition status is immediate or deferred as follows:
1-8
SCSI REFERENCE
1009566-001
1.6 COMMAND STATUS
If status for the command is to be returned when the command is
completed, Check Condition status is reported when the condition occurs
(immediate error reporting).
If status for the command was returned when the command was initiated
(that is, before the condition occurred), Check Condition status is reported
when the next command is received from the same initiator (deferred error
reporting).
If the condition occurs while the command is executing and the tape drive
is disconnected from the initiator, Check Condition status is reported to the
initiator after the reconnect process.
For specific situations that return Check Condition status, refer to the
command descriptions in Chapter 3 through Chapter 26.
Check Condition status is reported when a command is received in the
following cases:
There is a bus parity error or format check error in a CDB.
The command is the first command sent to the tape drive after it was reset
by a SCSI bus reset or a Bus Device Reset message or after the data cartridge
was replaced. The sense key in the sense data indicates Unit Attention (6h).
A threshold comparison is enabled and a log counter has overflowed.
Always issue a REQUEST SENSE command to determine the cause of the
Check Condition status.
1.6.3
BUSY
Busy status indicates that the tape drive is in the busy state. The tape drive is
in a busy state when it is performing an internal operation that will not allow
another command to be accepted until the operation is complete.
The tape drive returns Busy status for a command request until the busy state
is released. For this reason, the initiator must reissue the command to the tape
drive. Once the busy state is released, selection operation and commands can
be executed normally.
1.6.4
RESERVATION CONFLICT
Reservation Conflict status indicates that the tape drive is currently reserved
for the exclusive use of another initiator. This status is reported until the
initiator that reserved the tape drive issues a RELEASE UNIT command or a
reset condition occurs.
Note: The tape drive does not report Reservation Conflict status for REQUEST
SENSE (03h) or INQUIRY (12h) commands.
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CHAPTER 1 SCSI COMMAND PROTOCOL OVERVIEW
1.7
CONVERTING AN EXISTING VXA-1 DRIVER
If you have been supporting the VXA-1 tape drive and want to convert an
existing driver to provide support for the VXA-2 tape drive, you need to
consider the changes summarized in Table 1-3.
Table 1-3 Converting an existing VXA-1 device driver to a VXA-2 device driver
Consider these differences between VXA-1 and VXA-2 when
implementing device driver changes...
Look here for more
information....
The following changes have been made in the INQUIRY command: Chapter 4, “INQUIRY (12h)”
ƒ Byte 07, Bit 5 – Wbus16 of the Inquiry data is always 1, indicating
that the drive supports 16-bit wide transfers on the SCSI bus. In
VXA-1, this bit is 0 if a narrow configuration is being used and 1 if
a wide configuration is being used.
ƒ Check the value of the Vendor Identification field (bytes 8 through
15) in the Standard Inquiry Data. The value returned by the VXA-2
tape drive is EXABYTE, followed by one ASCII space character.
ƒ Check the product identification value returned by the VXA-2 tape
drive in the Inquiry data. The value returned for bytes 16 through
31 is VXA-2, followed by 11 ASCII space characters.
ƒ Support for the Device Identification page (Page Code 83) has been
added.
The following changes have been made in the MODE SELECT and Chapter 9, “MODE SELECT (15h)”
MODE SENSE commands:
ƒ The VXA-2 tape drive supports additional tape lengths and formats.
A new Firmware Download Mode (100b) has been added to the
WRITE BUFFER command.
1-10
SCSI REFERENCE
Chapter 25, “WRITE BUFFER
(3Bh)”
1009566-001
2
IMPLEMENTING TAPE DRIVE
OPERATIONS
This chapter explains how to implement common tape drive operations in
your application. It includes information about the following:
Data cartridges for the VXA-2 tape drive
Using data compression
Setting the size of logical blocks
Using filemarks and setmarks
Maximizing data transfer efficiency
Formatting and using partitioned tapes
Handling Unit Attention conditions
Resetting the tape drive
2.1
DATA CARTRIDGES FOR THE VXA-2 TAPE DRIVE
The VXA-2 tape drive reads and writes to VXAtape AME (advanced metal
evaporated) cartridges in either VXA-1 or VXA-2 format. Table 2-1 provides the
approximate data capacities for each cartridge when written in VXA-2 format.
Note:
Tapes written in VXA-2 format cannot be read by VXA-1 tape drives.
Table 2-1 VXAtape cartridge capacities in gigabytes (GB)
a
OCTOBER 2008
Cartridge
Model
Capacity, Native
Capacity, Compresseda
Tape Length
V23
80 GB
160 GB
230 meters
V17
59 GB
118 GB
170 meters
V10
37 GB
74 GB
107 meters
V6
21.5 GB
43 GB
62 meters
Assumes a 2:1 compression ratio. Actual compressed capacity varies depending on the type of data being
recorded.
VXA-2 TAPE DRIVE
2-1
CHAPTER 2 IMPLEMENTING TAPE DRIVE OPERATIONS
2.1.1
LOADING A DATA CARTRIDGE
When you insert a data cartridge into the tape drive, the following actions
occur.
1. The tape drive automatically loads the tape into the tape path.
2. The tape drive reads the logical format record at the beginning of the tape
or determines that the tape is blank.
3. The tape drive positions the tape at the logical beginning of partition 0
(LBOP).
4. The tape drive goes to the tape ready, idle state (LEDs 2 and 4 on).
Note: Do not insert a cartridge until the tape drive has finished its power-on
self-test (indicated when LED 4 is green). The tape drive will not accept a
cartridge if you try to insert it before POST is complete.
2.1.2
UNLOADING A DATA CARTRIDGE
When you press the eject button or issue an UNLOAD command (1Bh), the
following actions occur (assuming that a data cartridge is loaded and the tape
drive is ready).
Note: If you previously issued a PREVENT/ ALLOW MEDIUM REMOVAL
command to prevent media removal, the tape drive does not perform the
unload operation when you press the eject button.
1. The tape drive completes any command or operation currently in progress.
2. The tape drive writes any buffered information to tape, then writes an EOD
mark to indicate the end of data.
3. The tape drive writes the updated logical format record at the beginning of
the tape.
4. The tape drive rewinds the tape to the physical beginning of tape (PBOT).
5. The tape drive unloads the tape from the tape path.
6. The tape drive ejects the data cartridge.
Status Reported for Unload Procedure
If you issue a command to the tape drive during the unload procedure, the
tape drive returns Check Condition status with the sense key set to Unit
Attention (6h). After reporting a Unit Attention condition, the tape drive
returns Check Condition with the sense key set to Not Ready (2h) for all
subsequent commands (except INQUIRY and REQUEST SENSE). (For
information about clearing a Unit Attention condition, see page 2-10.)
2-2
SCSI REFERENCE
1009566-001
2.2 USING DATA COMPRESSION
Error During Unload Procedure
If an error occurs before or during the unload procedure, the tape drive
suspends the unload sequence; LEDs 1 and 3 change to yellow to indicate an
error. If you press the eject button again, the tape drive reattempts the unload
sequence. Be aware that unwritten data in the buffer will not be written to
tape. The buffer and any errors will be cleared.
Note: The tape drive will not eject the cartridge until it has successfully written
the logical format record to tape.
2.2
USING DATA COMPRESSION
The VXA-2 tape drive writes data in either VXA-2 or VXA-1 format. By default,
data is compressed when it is written. The VXA-2 tape drive uses an Adaptive
Lossless Data Compression (ALDC) algorithm to compress data at an average
ratio of 2:1. However, the actual compression ratio may be higher or lower
depending on the type of data.
You can use the DCE (data compression enable) bit of the MODE SELECT
command to specify compressed or uncompressed format at any position on
the tape (see page 9-11).
2.3
SETTING THE SIZE OF LOGICAL BLOCKS
Logical blocks are the basic units of data transfer between the initiator and the
tape drive.
When you use the WRITE or READ commands, you can specify fixed-length
or variable-length logical blocks. If you write or read fixed-length logical
blocks, you can transfer one or more logical blocks with each command. You
specify the block length using the Block Length field in the Block Descriptor of
the MODE SELECT command. If you write or read variable-length logical
blocks, you transfer just one logical block with each command. You specify the
block length in the Transfer Length field of the WRITE or READ command.
You can set the size of the logical data blocks to values between 0 and 240 KB.
However, for optimum tape drive efficiency, keep the following factors in
mind when choosing the logical block size:
For variable-length logical blocks or fixed-length logical blocks, select a block
size that ensures that the data transferred in a single variable length block or
in a set of fixed-length blocks is greater than or equal to 32 KB; transferring
at least 64 KB of data at a time provides optimal data compression.
For fixed-length logical blocks, only block lengths that are multiples of
4 bytes are valid. Regardless of the block size you select, always make sure
that at least 32 bytes of data are transferred with each command. A block
length of 0 is invalid for fixed-length blocks.
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CHAPTER 2 IMPLEMENTING TAPE DRIVE OPERATIONS
For variable-length logical blocks, the minimum block size is 1 byte.
However, using a very small block size will affect the tape drive’s
performance. Try to use a block size no smaller than 32 KB. In general, larger
logical blocks transfer more efficiently than smaller logical blocks.
If you use logical blocks that are smaller than the recommended range, tape
drive efficiency is reduced in the following areas:
Tape capacity. The tape drive adds header and error correction information
to each logical block set it writes to tape during each transfer. If you use very
small logical block sets, significant overhead is added to the data recorded
on the tape.
Compression. The tape drive compresses data on a block-by-block basis by
building a translation table for each logical block. Very small logical blocks
slightly reduce compression efficiency because a new table has to be built for
each block.
2.4
USING FILEMARKS AND SETMARKS
Filemarks and setmarks enable an initiator to locate particular blocks of data
using high-speed search. When writing data to tape, an initiator can use
WRITE FILEMARKS commands to write filemarks or setmarks to indicate data
boundaries. When reading the tape, the initiator can use a SPACE command to
position the tape to data marked by a filemark at high speeds.
Setmarks provide an additional way to indicate data boundaries on the tape;
in a sense, they can be thought of as a “hierarchically superior” filemark. You
can use a MODE SELECT (15h) command to suppress setmark detection
during read, verify, space block, and space filemark operations. The setmark is
the same length as the filemark. For additional information about using
setmarks, refer to Chapter 26, “WRITE FILEMARKS (10h).”
2.5
MAXIMIZING DATA TRANSFER EFFICIENCY
When reading or writing data, the tape drive can operate in either streaming
or start/pause mode, depending on the data transfer rate of the host system.
Streaming occurs when the data transfer rate to or from the host is greater
than or equal to the tape drive’s own data transfer rate, allowing the drive to
read or write data in a continuous stream. When the host’s data transfer rate is
less than the tape drive’s data transfer rate, the tape drive must operate in
start/pause mode as it waits for data transfer to or from the host.
2-4
SCSI REFERENCE
1009566-001
2.6 FORMATTING AND USING PARTITIONED TAPES
Streaming Mode When operating in streaming mode, the tape drive
transfers data continuously (to tape or to the host) without stopping tape
motion. If your system permits, operating the tape drive in streaming mode
can maximize the amount of data you can store on a tape and minimize the
amount of wear on the tape and recording heads. To enable the tape drive to
operate in streaming mode, the host must be able to transfer data at a
minimum of 6 MB per second if the tape drive is writing uncompressed data
or approximately 12 MB per second if the tape drive is writing compressed
data.
During streaming operation, the tape drive adapts to variations in the host’s
data transfer rate by disconnecting from and reconnecting to the SCSI bus, as
follows:
During a write operation, if the tape drive’s buffer fills with data from the
host faster than the tape drive can write the data to tape, the tape drive
disconnects from the SCSI bus while continuing to write data until the
amount of space available in the buffer is equal to the reconnect threshold.
The tape drive then reconnects to the SCSI bus to accept more data.
During a read operation, if the host can accept data from the tape drive’s
buffer faster than the tape drive can fill the buffer with data from the tape,
the tape drive disconnects from the SCSI bus until it has filled the buffer
back up to a level equal to the reconnect threshold. Then the tape drive
reconnects to the SCSI bus to transfer more data.
Start/Pause Mode When operating in start/pause mode, the tape drive
pauses and restarts tape motion to accommodate a slow host transfer rate. The
tape drive determines when to restart tape motion by comparing how full the
buffer is to the motion threshold, as follows:
During a write operation, the tape drive waits until the buffer is filled to a
certain level (the motion threshold), starts the tape and records the buffered
data. When the buffer is empty, the tape drive pauses tape motion until the
buffer can be filled again by the host. The tape drive then resumes writing
data at the point where it paused.
During a read operation, the tape drive fills the buffer with data from the
tape, pauses the tape motion, waits for the host to accept enough data to
empty the buffer to the motion threshold, then restarts the tape motion and
fills the buffer again.
2.6
FORMATTING AND USING PARTITIONED TAPES
The VXA-2 tape drive can write and read tapes containing one or two
partitions. A partition is a self-contained writable and readable area on a tape.
A standard tape is considered a single-partition tape. That is, there are no
divisions on the tape; the entire capacity of the tape is dedicated to a single
data set, regardless of how large that set is. When data at the beginning of the
partition is overwritten, any previously written data past the new end of data
(EOD) mark on the tape becomes inaccessible.
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CHAPTER 2 IMPLEMENTING TAPE DRIVE OPERATIONS
A multi-partition tape is a tape that has been divided into two separate
writable and readable areas (partitions). When data is recorded on a
partitioned tape, each partition is treated as a separate “virtual” tape. When
data in one partition is overwritten, data in other partitions on the tape is still
accessible. Each partition can be updated and rewritten without affecting the
data in the other partitions. Note that partitions are not the divisions between
separate areas on the tape; rather, they are the separate areas themselves.
Each partition on a tape contains a logical and physical beginning (LBOP and
PBOP) and a logical and physical end (LEOP and PEOP). The tape drive
considers each partition a completely self-contained recording area
independent of the other partition on the tape. The tape drive cannot move
the tape beyond the beginning or end of a partition unless specifically
requested to by a LOCATE (2Bh) or MODE SELECT (15h) command. In effect,
the tape drive treats each partition as if it were a separate tape.
2.6.1
CREATING A PARTITIONED TAPE
To create a partitioned tape, you format the tape using the Medium Partition
page (Page Code 11h) of the MODE SELECT (15h) command. The Medium
Partition page lets you specify whether there are one or two partitions on the
tape. If only one partition is selected, the partition encompasses the entire
tape.
A standard blank tape is considered to have one partition. You do not need to
format a blank tape if you want only one partition. The only time you would
specify one partition when you are formatting a tape is if you want to change a
two-partition tape back to a single-partition tape.
The following is a summary of the steps you take to create two partitions on an
unformatted (or single-partition) tape. (Refer to Chapter 9 for specific details
about using the MODE SELECT command.)
1. Load a tape into the tape drive, or rewind the current tape to the logical
beginning of tape (LBOT). The tape must be positioned at LBOT or at the
logical beginning of a partition (LBOP) before you can format the tape with
new partitions.
2. Issue a MODE SELECT command and specify page format (PF=1). Specify
the following parameters for the partitions in the Medium Partition page
(Page Code=11h):
Set the Additional Partitions Defined field to 1 to indicate that you want
to define one partition in addition to the original partition (the entire
tape).
2-6
SCSI REFERENCE
1009566-001
2.6 FORMATTING AND USING PARTITIONED TAPES
Set FDP (Fixed Data Partitions), SDP (Select Data Partitions), or IDP
(Initiator Defined Partitions) to 1 depending on how you want the size
of the partitioned determined. (Note that you can set only one of these
fields.) If FDP=1, the partition will encompass the entire tape, resulting
in a single-partition tape. If SDP=1, partition 1 will be 100 MB and
partition 0 will encompass the remainder of the tape. If IDP=1, the
partitions will be the size you specify.
If you choose to define the partition sizes yourself (IDP=1), use PSUM
(Partition Size Unit of Measure) to specify the units of measure you will
use to specify the size. Use the Partition Size fields to specify each
partition’s size. (Note that if you specify a total value for the Partition
Sizes that is larger than the amount of space available on the tape, the
format will fail with a sense key of Illegal Request (5h).)
3. Wait for the formatting process to be completed (several minutes
depending on the partition sizes). When the tape drive has finished
formatting the tape, it will position the tape at the beginning of the default
partition (the last partition on the tape). At this point, you can begin writing
data or performing other tape operations as described in the following
section.
2.6.2
USING A MULTI-PARTITION TAPE
The easiest way to use a multi-partition tape is to think of it as separate tapes.
Just as you would have to physically change tapes to access data on another
tape, you have to specifically request that the tape be moved to another
partition before you can perform actions in that partition. The following
sections describe how to perform several typical actions on a multi-partition
tape.
Loading a Partitioned Tape
You load a multi-partition tape exactly as you would a standard tape. By
default, the tape drive positions to the LBOP for the last partition on the tape
(partition 0).
Changing Partitions
If you want to move the tape from one partition to the logical beginning of
another partition (LBOP), use either of the following methods:
Note: The tape drive repositions the tape immediately, regardless of the method
used to change partitions.
Method 1 – LOCATE command
following parameters:
Issue a LOCATE (2Bh) command. Specify the
Set CP (Change Partitions) to 1 to indicate you want to change partitions.
For Block Address, specify the block to which you want the tape moved.
Set Partition to the number of the partition to which you want to change.
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CHAPTER 2 IMPLEMENTING TAPE DRIVE OPERATIONS
Method 2 – MODE SELECT command Issue a MODE SELECT (15h)
command. Specify page format (PF=1) and send the Device Configuration
page (Page Code=10h). Specify the following parameters:
Set CAP (Change Active Partition) to 1 to indicate that you want the tape to
be moved to another partition.
Set Active Partition to the number of the partition to which you want to
move.
Writing Data in Partitions
To write data, use the WRITE (0Ah) command as you would with a standard
tape. However, remember that if you want to write data in the partition the
tape is not currently in, you must first use the LOCATE or MODE SELECT
command to change partitions, as described in the previous section.
When you are writing data to a partition, you can not write data past the end
of the partition. If the tape drive encounters the logical end of the partition
(LEOP), it returns Check Condition status, just as it does when it encounters
the logical end of the tape (LEOT). Similarly, you cannot write past physical
end of the partition (PEOP) when you choose to write data all the way to
PEOP. If the tape drive encounter PEOP while writing data, it reacts just as it
does when it encounters the physical end of the tape (PEOT). The write
operation stops and any buffered data is not written to tape.
Locating Data Blocks in Partitions
Use the READ POSITION (34h) command to identify the position of a specific
data block on a partitioned tape as you would on a standard tape. The READ
POSITION data returned by the tape drive indicates the block address at the
current location. It also indicates the partition number for the current location.
When you use the LOCATE (2Bh) command on a partitioned tape, you must
first specify in which partition the tape drive should search for the requested
block. If you need to change partitions, set the CP (Change Partition) bit to 1
and specify the number of the partition to which you want the tape moved in
the Partition field. The tape drive moves the tape to the requested partition,
then searches for the requested block.
Reading Data on a Partitioned Tape
To read data, use the READ (08h) command just as you would with a standard
tape. However, remember that if you want to read data in a partition the tape
is not currently in, you must use the LOCATE or MODE SELECT command to
reposition the tape to that partition. After you have issued a command to
relocate to a new partition, you can use a LOCATE command or SPACE
command to move the tape to a legal position for reading data.
2-8
SCSI REFERENCE
1009566-001
2.7 HANDLING UNIT ATTENTION CONDITIONS
Rewinding a Partitioned Tape
When you issue a REWIND (01h) command, the tape drive rewinds the tape
to the beginning of the current partition. If the tape is positioned in the first
partition on the tape (partition 1), the tape drive rewinds the tape to the logical
beginning of the tape (LBOT).
If you want to rewind the tape to LBOT and the tape is positioned in
partition 0 (the last partition on the tape), do not use the REWIND command.
Instead, use the LOCATE command to position the tape to the logical
beginning of partition (LBOP) for partition 1.
Erasing a Partitioned Tape
The ERASE command acts on only one partition at a time. After erasing the
partition, the tape drive rewinds the tape to the beginning of that partition. To
erase the data from an entire tape without eliminating the partitions, you must
erase each partition separately.
Erasing Data From One Partition If you want to erase the data from just one
partition, use the ERASE command as you would with a standard tape. Start
from the beginning of the partition you want to erase and issue the ERASE
command. The tape drive rewrites the LBOP information, then erases forward
from LBOP until it reaches the end of the partition. It then rewinds to LBOP.
When you erase the data from one partition, no data in other partitions is
erased.
Erasing the Entire Tape If you want to erase the entire tape, you can erase
each partition separately and preserve the partition information. Or, you can
reformat the tape as a single-partition tape, then erase the entire tape.
!
Important
If you reformat a partitioned tape to create a single-partition
tape, all of the information defining the original partitions is
erased. However, the actual data is not erased and remains on
the tape (although it is not accessible by commercial software).
For this reason, if you are concerned about data remaining on
a tape, do not use reformatting as a way to erase data. You
must explicitly perform a long erase operation to erase the data
after reformatting the tape to remove the partition information
(see page 3-2–”If you want to erase the...”).
Unloading a Partitioned Tape
The UNLOAD command works exactly as it would for a standard tape. You
can issue the UNLOAD command from any partition. The tape drive rewinds
the tape to the physical beginning of tape (PBOT), unloads the tape from the
tape path, and ejects the cartridge.
2.7
HANDLING UNIT ATTENTION CONDITIONS
The tape drive creates a Unit Attention condition for each initiator when any
of the following conditions occurs:
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CHAPTER 2 IMPLEMENTING TAPE DRIVE OPERATIONS
A data cartridge is inserted and automatically loaded.
A data cartridge is inserted and rejected because the media is incompatible
with the tape drive.
The eject button is pressed and the data cartridge is ejected.
The MODE SELECT parameters are changed by an initiator other than the
one attempting to communicate with the tape drive.
The tape drive is reset or powered off and back on again (see page 2-11).
A log parameter (counter) reaches a specified threshold value — assuming
that the Report Log Exception Condition (RLEC) bit on the MODE SELECT
Control Mode page is set to 1.
The internal microcode (firmware) is changed by a SCSI download (WRITE
BUFFER command).
2.7.1
EFFECT OF CHANGING DATA CARTRIDGES
When you press the eject button to remove a cartridge from the tape drive, the
tape drive first rewinds the tape to the PBOT and unloads it from the tape
path. When the eject operation is complete, the tape drive returns Check
Condition status with the sense key set to Not Ready (2h) to all subsequent
commands that require tape motion.
When you insert a data cartridge, the tape drive loads the tape into the tape
path and positions it at LBOP for partition 0. When the load operation is
complete, the tape drive returns Check Condition status with the sense key set
to Unit Attention (6h) to all initiators on the bus.
2.7.2
CLEARING THE UNIT ATTENTION CONDITION
A Unit Attention condition persists for each initiator until that initiator issues
any command other than INQUIRY (12h) or REQUEST SENSE (03h).
First Command Received after Unit Attention
If the first command received after a Unit Attention condition occurs is an
INQUIRY or REQUEST SENSE command, the tape drive executes the
command, reports any pending status, and preserves the Unit Attention sense
data. If the first command is any other command, the tape drive does not
execute the command and returns Check Condition status with the sense key
set to Unit Attention (6h).
Next Command Received after Unit Attention
If the next command received after a Unit Attention is reported is a REQUEST
SENSE or an INQUIRY command, the tape drive executes the command and
preserves the Unit Attention sense data. If the next command is any other
command, the command is executed and the Unit Attention sense data is
cleared.
2-10
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1009566-001
2.8 RESETTING THE TAPE DRIVE
Note: If multiple Unit Attention conditions occur before the initiator selects the
tape drive, each Unit Attention condition is presented sequentially in the
order that it occurred.
2.8
RESETTING THE TAPE DRIVE
You can use any of the following methods to reset the tape drive:
Power the tape drive off and back on again (power-on reset).
Press and hold the eject button for at least 10 seconds, then release the
button. The tape drive first unloads and ejects any cartridge that is in the
tape drive (unless a hardware error occurred), then resets the tape drive.
Send a RST pulse on the SCSI bus for a minimum of 25 μsec (SCSI bus reset).
A SCSI bus reset immediately clears all devices from the bus, resets their
associated equipment, and terminates all pending I/O processes.
Issue a Bus Device Reset (0Ch) message to the tape drive (device reset). A
device reset clears the tape drive from the bus, causes all commands sent to
it to be cleared, and terminates all pending I/O processes.
Note: If a SCSI bus or device reset occurs during a power-on reset, the power-on
reset operation will be restarted.
2.8.1
EFFECT OF POWER-ON RESET
Performing a power-on reset causes the tape drive to complete its power-on
self-test. A power-on reset also has the following effects:
If the tape drive is connected to the SCSI bus, the SCSI bus goes to the Bus
Free phase.
The checksum of the control code is verified.
The servo is reset and a servo self-test is performed.
All tape drive parameters are reset to their default states.
A test of the microprocessor's external memory is performed.
A buffer memory test is performed.
After a power-on reset, the tape drive will respond on the SCSI bus within
three seconds.
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CHAPTER 2 IMPLEMENTING TAPE DRIVE OPERATIONS
2.8.2
EFFECT OF SCSI BUS AND DEVICE RESETS
If the tape drive is set for buffered operation (see page 9-3) and there is data in
the buffer from a WRITE or WRITE FILEMARKS command, the tape drive
writes the buffered data to tape before resetting. Then, if the tape drive is
connected to the SCSI bus, the SCSI bus goes to the Bus Free phase. After a
SCSI bus or device reset, the tape drive will respond on the SCSI bus within
250 msec.
!
Important
2.8.3
If the device that supplies SCSI bus terminator power is
powered off, the RST line may be left in an indeterminate state
(either reset or not, depending on the voltages). It may be
impossible to communicate with the tape drive or to unload a
data cartridge when the device is in this state. To remove the
data cartridge, restore power to the terminating device or
remove the SCSI cable from the tape drive to allow
independent tape drive operation.
RESET PROCESSING
The tape drive processes resets differently depending on whether a data
cartridge is present or not.
Data Cartridge Present before Reset
If a data cartridge is present before the reset occurs and the tape has only one
partition, the tape drive rewinds the tape and positions it at the beginning of
the partition. If the tape has more than one partition, the tape drive rewinds
the tape then positions it at the logical beginning of the partition (LBOP) of the
default partition. When the reset is complete, the tape drive is ready to process
tape motion commands.
When a data cartridge is present, the tape drive responds to the reset as
follows:
It returns Check Condition status to the first command received. The sense
key is set to Unit Attention (6h), and the Additional Sense Code (ASC) and
Additional Sense Code Qualifier (ASCQ) fields indicate that a reset
occurred.
It processes all non-motion commands. The default status returned by the
TEST UNIT READY (00h) command is Check Condition status with the
sense key set to Not Ready (2h). The ASC and ASCQ fields indicate that the
device is becoming ready.
If it receives tape motion commands, the tape drive queues (holds) one tape
motion command from each initiator (and disconnects, if allowed) until the
reset operation is complete and the tape is loaded. Once the load is
complete, it processes the queued commands.
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2.8 RESETTING THE TAPE DRIVE
If the tape is already rewound when the reset occurs, the reset takes about one
minute to complete. Additional time is required if the tape drive needs to
rewind the tape.
Data Cartridge Not Present before Reset
When a data cartridge is not present, the tape drive responds to the reset as
follows:
It returns Check Condition status to the first command received. The sense
key is set to Unit Attention (6h), and the ASC and ASCQ fields indicate that
a reset occurred.
It processes all non-motion commands. The TEST UNIT READY (00h)
command returns Check Condition status with the sense key set to Not
Ready (2h). The ASC and ASCQ fields indicate that no tape is present.
It returns Check Condition status to all tape motion commands. The sense
key is set to Not Ready (2h), and the ASC and ASCQ fields indicate that no
tape is present.
!
OCTOBER 2008
Important
After a reset, do not insert a cartridge into the tape drive until
the LEDs indicate that the tape drive is ready (LED 4 is green,
all others are off). The tape drive will not accept a cartridge if
you try to insert one before the LEDs are off.
VXA-2 TAPE DRIVE
2-13
CHAPTER 2 IMPLEMENTING TAPE DRIVE OPERATIONS
Notes
2-14
SCSI REFERENCE
1009566-001
3
ERASE (19h)
Bit
Byte
00
7
6
5
4
3
2
1
0
0
0
0
1
1
0
0
1
Immed
Long
Logical Unit Number
01
Reserved
02
Reserved
03
04
Control
05
3.1
ABOUT THIS COMMAND
The ERASE command causes the tape drive to perform one the following
types of erase operations:
A short erase (byte 01, bit 0 equals zero) clears the partition information and
writes an EOD at the logical beginning of the partition (LBOP).
A long erase (byte 01, bit 0 equals one) erases all data from the tape (long
erase), starting at the current valid tape position to the physical end of tape
(PEOT) or, if the tape is partitioned, to the physical end of the current
partition (PEOP).
When the erase operation is successfully completed, the tape drive
automatically rewinds the tape to the logical beginning of tape (LBOT) or, if
the tape is partitioned, to the logical beginning of the current partition
(LBOP).
The tape drive performs the erase operation at the same speed as it performs
the READ and WRITE commands.
OCTOBER 2008
VXA-2 TAPE DRIVE
3-1
CHAPTER 3 ERASE (19h)
Notes:
If the ERASE command is received after a WRITE (0Ah) or WRITE FILEMARKS
(10h) command, the tape drive writes any buffered data, filemarks, and setmarks
to tape before performing the erase operation. If an error occurs while it is
writing the buffered data to the tape, the tape drive returns Check Condition
status and does not perform the erase operation.
To erase all of the data from a partitioned tape without eliminating the partition
information, you must erase each partition separately.
If you want to erase the entire tape, you can erase each partition separately
and preserve the partition information. Or, you can reformat the tape as a
single-partition tape, then erase the entire tape.
!
3.2
If you reformat a partitioned tape to create a single-partition tape, all of
the information defining the original partitions is erased. However, the
actual data is not erased and remains on the tape (although it is not
accessible by commercial software). For this reason, if you are
concerned about data remaining on a tape, do not use reformatting as
a way to erase data. You must explicitly perform a long erase operation
to erase the data after reformatting the tape.
Important
CDB FIELD DEFINITIONS
Logical Unit Number (LUN) – Byte 01, Bits 7 through 5
The tape drive only supports LUN 0. The value for this field must be 0.
Byte 01, Bit 1 – Immed
This bit determines when command status is returned to the initiator:
0
Status is returned when the ERASE command is completed
1
Status is returned when the ERASE command is started
If the buffer contains data from a previous WRITE command, the tape drive
does not execute the ERASE command until the data in the buffer is written to
the tape and an EOD mark is appended. The tape drive then performs the
erase operation as follows:
If the Immed bit is set to 1, the tape drive returns Good status and performs
the erase operation.
If the Immed bit is set to 0, the tape drive returns status when the erase and
rewind operations are complete.
3-2
SCSI REFERENCE
1009566-001
3.3 TAPE POSITIONING
Byte 01, Bit 0 – Long
This bit determines the amount of tape to be erased, as follows:
3.3
0
The partition information is cleared and an EOD mark is
written at the logical beginning of the partition (LBOP). No
data is erased. The tape drive returns Good status.
1
The partition information and the data for the current
partition is erased beginning at the current position to the
physical end of partition (PEOP).
TAPE POSITIONING
The ERASE command can only be performed at the following valid tape
positions:
Logical beginning of partition (LBOP)
End of data mark (EOD)
Beginning of tape (BOT) side of a filemark
End of tape (EOT) side of a filemark
BOT side of a setmark
EOT side of a setmark
3.4
EXCEPTIONS AND ERROR CONDITIONS
Table 3-1 lists exceptions and error conditions that cause the tape drive to
return Check Condition status for the ERASE command.
Table 3-1 REQUEST SENSE data for ERASE command errors and exceptions
Sense
ASC
ASCQ Explanation
Key (Byte 12) (Byte 13)
02h
04h
01h
Not Ready. Logical unit not ready, but is in process of becoming ready
(rewinding or loading tape).
02h
3Ah
00h
Not Ready. Logical unit not ready. Command requires a tape, and no tape
is present.
03h
30h
02h
Medium Error. The tape format is incompatible with the tape drive
hardware or microcode.
03h
31h
01h
Medium Error. The tape format is corrupted.
03h
50h
00h
Medium Error. The tape drive could not locate a valid splice location on
the tape. The tape is not located at a valid write position or the tape drive
could not locate the valid write position.
04h
15h
01h
Hardware Error. The tape drive cannot position the tape correctly.
04h
51h
00h
Hardware Error. The erase operation failed.
06h
30h
00h
Unit Attention. Incompatible media was rejected after the cartridge was
inserted.
07h
27h
00h
Data Protect. Attempted to erase a data cartridge that is write protected.
OCTOBER 2008
VXA-2 TAPE DRIVE
3-3
CHAPTER 3 ERASE (19h)
Notes
3-4
SCSI REFERENCE
1009566-001
4
INQUIRY (12h)
Bit
Byte
00
7
6
5
4
3
2
1
0
0
0
0
1
0
0
1
0
Logical Unit Number
01
Reserved
02
Page Code
03
Reserved
04
Allocation Length
05
Control
4.1
EVPD
ABOUT THIS COMMAND
The INQUIRY command requests that information about the tape drive’s
parameters be sent to the initiator.
4.2
CDB FIELD DEFINITIONS
Logical Unit Number (LUN) – Byte 01, Bits 7 through 5
The tape drive only supports LUN 0. The value for this field must be 0.
Byte 01, Bit 0 – EVPD (Enable Vital Product Data)
This field indicates the type of Inquiry data being requested by the initiator, as
follows:
OCTOBER 2008
0
Return Standard Inquiry Data. The value of the Page Code
field (byte 02) must be 0.
1
Return one of the Vital Product Data pages, based on the
value of the Page Code field.
VXA-2 TAPE DRIVE
4-1
CHAPTER 4 INQUIRY (12h)
Byte 02 – Page Code
This field specifies the page number of the Vital Product Data page to be
returned to the initiator, as follows:
00h
Supported Vital Product Data page
80h
Unit Serial Number page
83h
Device Identification page
C0h
Original Inquiry Data page
If the EVPD bit (byte 1, bit 0) is set to 0, the Page Code must be 00h.
Byte 04 – Allocation Length
This field specifies the number of bytes allocated by the initiator for the
Inquiry data returned by the tape drive. Any value between 00h and FFh is
valid. An allocation length of 00h indicates that no data is to be returned.
The tape drive terminates the Data In phase when the number of bytes
specified in the Allocation Length field has been transferred or when all
available Inquiry data has been transferred, whichever is less.
4.3
WHAT THE TAPE DRIVE RETURNS
The data returned by the tape drive depends on the values specified in the
INQUIRY CDB. Table 4-1 summarizes the values you must specify in the
INQUIRY CDB to return the different types of Inquiry data.
Table 4-1 CDB values for different types of Inquiry data
To return this Inquiry
data...
Standard Inquiry Data
Set these fields to...
EVPD
And specify this value for
Page Code the Allocation Length...
Number of bytes
returned (hex)
0
00h
any value from 0 to FFh
0 to 108 bytes
(00h to 6Ch)
Supported Vital Product
Data page
1
00h
08h
8 bytes (08h)
Unit Serial Number page
1
80h
10h
16 bytes (10h)
Device Identification
page
1
83h
2Ah
44 bytes (2Ch)
Original Inquiry Data
page
1
C0h
6Ch
108 bytes (6Ch)
4-2
SCSI REFERENCE
1009566-001
4.3 WHAT THE TAPE DRIVE RETURNS
4.3.1
STANDARD INQUIRY DATA
The tape drive returns the Standard Inquiry Data when the EVPD bit in the
CDB is 0.
Bit
Byte
7
6
5
3
Peripheral Qualifier
00
RMB
01
AERC
03
2
1
0
Peripheral Device Type
Device-Type Modifier
ISO Version
02
ECMA Version
ANSI Version
Reserved
Response Data Format
Additional Length
04
05
Reserved
06
07
4
RelAdr
WBus32
WBus16
Sync
Linked
RSVD
CmdQue
SftRe
08
...
Vendor Identification
15
16
...
Product Identification
31
32
...
Product Revision Level
35
36
...
Vendor Specific
55
56
…
Reserved
95
96
…
Unit Serial Number
107
OCTOBER 2008
VXA-2 TAPE DRIVE
4-3
CHAPTER 4 INQUIRY (12h)
Byte 00, Bits 7 through 5 – Peripheral Qualifier
The Peripheral Qualifier indicates whether a device of the type specified in
Peripheral Device Type field is currently connected to the specified logical unit
(LUN), as follows:
000b
The specified device type is currently connected to this
logical unit
011b
The LUN is invalid (the LUN in the CDB or in the Identify
message was not 0)
Byte 00, Bits 4 through 0 – Peripheral Device Type
The Peripheral Device Type identifies the device currently connected to the
specified logical unit (LUN), as follows:
00000b
The device (the tape drive) is a sequential access device
11111b
The device type is unknown or there is no device type (the
LUN in the CDB or in the Identify message was not 0)
Byte 01, Bit 7 – RMB (Removable Media)
The value returned for this field is 1, indicating that the media is removable.
Byte 01, Bits 6 through 0 – Device-Type Modifier
The tape drive does not support the Device-Type Modifier. The value for this
field is 0.
Byte 02, Bits 7 and 6 – ISO Version
The value returned for this field is 000b, indicating that the tape drive does not
claim compliance with the International Standardization Organization (ISO)
version of SCSI.
Byte 02, Bits 5 through 3 – ECMA Version
The value returned for this field is 000b, indicating that the tape drive does not
claim compliance with the European Computer Manufacturers Association
(ECMA) version of SCSI.
Byte 02, Bits 2 through 0 – ANSI Version
The value returned for this field is 2h, indicating that the tape drive supports
the current version of the ANSI SCSI-2 standard (X3T9/89-042).
Byte 03, Bit 7 – AERC (Asynchronous Event Reporting Capability)
The value returned for this field is 0, indicating that the tape drive does not
have asynchronous event notification capability.
4-4
SCSI REFERENCE
1009566-001
4.3 WHAT THE TAPE DRIVE RETURNS
Byte 03, Bits 3 through 0 – Response Data Format
The value returned for this field is 2h, indicating that the data found is in
accordance with the ANSI SCSI-2 standard.
Byte 04 – Additional Length
The value returned for this field is 67h, indicating that there are 103 bytes of
additional Inquiry data available to be returned.
Byte 07, Bit 7 – RelAdr (Relative Address)
The value returned for this field is 0, indicating that the tape drive does not
support relative addressing.
Byte 07, Bit 6 – WBus32
The value returned for this field is 0, indicating that the tape drive does not
support 32-bit-wide bus transfers.
Byte 07, Bit 5 – WBus16
The value returned for this field is 1, indicating that the tape drive supports
16-bit-wide bus transfers.
Byte 07, Bit 4 – Sync
The value returned for this field is 1, indicating that the tape drive supports
synchronous data transfer.
Byte 07, Bit 3 – Linked
The value returned for this field is 0, indicating that the tape drive does not
support linked commands.
Byte 07, Bit 1 – CmdQue
The value returned for this field is 0, indicating that the tape drive does not
support tag command queuing.
Byte 07, Bit 0 – SftRe (Soft Reset)
The value returned for this bit is 0, which indicates that the tape drive does not
support the soft reset alternative in response to a reset condition.
Bytes 08 through 15 – Vendor Identification
This field contains the ASCII representation of “EXABYTE”, followed by a
single space.
Bytes 16 through 31 – Product Identification
This field contains the ASCII representation of “VXA-2” followed by eleven
ASCII space characters to fill the field (for example, VXA-2___________,
where each “_” represents an ASCII space character).
OCTOBER 2008
VXA-2 TAPE DRIVE
4-5
CHAPTER 4 INQUIRY (12h)
Bytes 32 through 35 – Product Revision Level
This field contains the ASCII representation of a decimal number indicating
the current revision level of the tape drive (for example, “0001” or other
Tandberg Data revision levels).
Bytes 36 through 55 – Vendor Specific
This field contains information about the tape drive firmware, formatted as
follows: ___hhhhh_mmddyy_hhh_, where each “_” represents an ASCII space
character, hhhhh is the hexadecimal firmware version, mmyydd is the date of the
firmware build, and hhh is the hexadecimal firmware configuration.
Bytes 96 through 107 – Unit Serial Number
This field contains the ASCII representation of the tape drive’s twelve-digit
hexadecimal serial number (for example, 000000012ABC).
4.3.2
SUPPORTED VITAL PRODUCT DATA PAGE
(PAGE CODE 00h)
The tape drive returns the Supported Vital Product Data page when the EVPD
bit in the command CDB is 1 and the Page Code is 00h.
Bit
Byte
00
7
6
5
4
3
Peripheral Qualifier
2
1
0
Peripheral Device Type
01
Page Code
02
Reserved
03
Page Length
04
First Page Code Supported
05
Second Page Code Supported
06
Third Page Code Supported
07
Fourth Page Code Supported
Byte 00, Bits 7 through 5 – Peripheral Qualifier
The Peripheral Qualifier indicates whether a device of the type specified in
Peripheral Device Type field is currently connected to the specified logical unit
(LUN), as follows:
4-6
SCSI REFERENCE
000b
The specified device type is currently connected to this
logical unit
011b
The LUN is invalid (the LUN in the CDB or in the Identify
message was not 0)
1009566-001
4.3 WHAT THE TAPE DRIVE RETURNS
Byte 00, Bits 4 through 0 – Peripheral Device Type
The Peripheral Device Type identifies the device currently connected to the
specified logical unit (LUN), as follows:
00000b
The device (the tape drive) is a sequential access device
11111b
The device type is unknown or there is no device type (the
LUN in the CDB or in the Identify message was not 0)
Byte 01 – Page Code
The Page Code for the Vital Product Data page is 00h.
Byte 03 – Page Length
The value returned for this field is 04h, indicating that four bytes of additional
information are available, excluding this byte.
Byte 04 – First Page Code Supported
The value for this field is 00h, indicating support for the Vital Product Data
page.
Byte 05 – Second Page Code Supported
The value returned for this field is 80h, indicating support for the Unit Serial
Number page.
Byte 06 – Third Page Code Supported
The value returned for this field is 83, indicating support for the Device
Identification page.
Byte 07 – Fourth Page Code Supported
The value returned for this field is C0h, indicating support for a
vendor-specific Inquiry page defined as the Original Inquiry Data page.
OCTOBER 2008
VXA-2 TAPE DRIVE
4-7
CHAPTER 4 INQUIRY (12h)
4.3.3
UNIT SERIAL NUMBER PAGE (PAGE CODE 80h)
The tape drive returns the Unit Serial Number page when the EVPD bit in the
CDB is 1 and the Page Code is 80h.
Bit
Byte
00
7
6
5
4
3
Peripheral Qualifier
2
1
0
Peripheral Device Type
01
Page Code
02
Reserved
03
Page Length
04
…
Unit Serial Number
15
Byte 00, Bits 7 through 5 – Peripheral Qualifier
The Peripheral Qualifier indicates whether a device of the type specified in
Peripheral Device Type field is currently connected to the specified logical unit
(LUN), as follows:
000b
The specified device type is currently connected to this
logical unit
011b
The LUN is invalid (the LUN in the CDB or in the Identify
message was not 0)
Byte 00, Bits 4 through 0 – Peripheral Device Type
The Peripheral Device Type identifies the device currently connected to the
specified logical unit (LUN), as follows:
00000b
The device (the tape drive) is a sequential access device
11111b
The device type is unknown or there is no device type (the
LUN in the CDB or in the Identify message was not 0)
Byte 03 – Page Length
The value returned for this field is 0Ch, indicating that there are 12 bytes of
additional information available, excluding this byte.
Bytes 04 through 15 – Unit Serial Number
This field contains the ASCII representation of the tape drive’s twelve-digit
serial number in the format hhhhhhhhhhhh, where h is a hexadecimal digit (for
example, 000000012ABC).
4-8
SCSI REFERENCE
1009566-001
4.3 WHAT THE TAPE DRIVE RETURNS
4.3.4
DEVICE IDENTIFICATION PAGE (PAGE CODE 83h)
The Device Identification page allows the tape drive to report its device
identifiers, including its product name and serial number. The tape drive
returns the Device Identification page when the EVPD bit in the CDB is 1 and
the Page Code is 83h.
Bit
Byte
7
6
5
4
3
Peripheral Qualifier
00
2
1
Peripheral Device Type
01
Page Code
02
Reserved
03
Page Length (28h)
04
Reserved
Code Set
05
Reserved
Identifier Type
06
Reserved
07
Identifier Length (24h)
08
0
(MSB)
…
Device Identifier 1
(LSB)
43
Byte 00, Bits 7 through 5 – Peripheral Qualifier
The Peripheral Qualifier indicates whether a device of the type specified in
Peripheral Device Type field is currently connected to the specified logical unit
(LUN), as follows:
000b
The specified device type is currently connected to this
logical unit
011b
The LUN is invalid (the LUN in the CDB or in the Identify
message was not 0)
Byte 00, Bits 4 through 0 – Peripheral Device Type
The Peripheral Device Type identifies the device currently connected to the
specified logical unit (LUN), as follows:
OCTOBER 2008
00000b
The device (the tape drive) is a sequential access device
11111b
The device type is unknown or there is no device type (the
LUN in the CDB or in the Identify message was not 0)
VXA-2 TAPE DRIVE
4-9
CHAPTER 4 INQUIRY (12h)
Byte 01 – Page Code
The value for this field is 83h, identifying the current page as the Device
Identification page.
Byte 03 – Page Length
The value returned for this field is 28h, indicating that there are 40 bytes of
additional information available, excluding this byte.
Byte 04, Bits 3 through 0 – Code Set
The value returned for this field is 02h, which indicates that the Device
Identifier 1 field contains ASCII data.
Byte 05, Bits 3 through 0 – Identifier Type
The value returned for this field is 1h, indicating that the uniqueness of the
identifier field is the responsibility of the company identified in the Vendor
Identification field of Device Identifier 1 (bytes 08 through 15).
Byte 07 – Identifier Length
The value returned for this field is 24h, which indicates that the length of the
Device Identifier 1 field is 36 bytes, excluding this byte.
Byte 08 through Byte 43 – Device Identifier 1
This field contains the Device Identifier for the tape drive, as follows:
Bytes 08 through 15 – Vendor Identification The ASCII representation of
“EXABYTE”, followed by a single ASCII space character.
Bytes 16 through 31 – Product Identification This field contains the ASCII
representation of “VXA-2” followed by a single space, an eight-digit
firmware version, and then two additional spaces to fill the field (for
example, VXA-2_nnnnnnnn__, where each “_” represents an ASCII space
character and nnnnnnnn represents the firmware version).
Bytes 32 through 43 – Unit Serial Number This field contains the ASCII
representation of the tape drive’s twelve-digit serial number in the format
hhhhhhhhhhhh, where h is a hexadecimal digit (for example, 000000012ABC).
4.3.5
ORIGINAL INQUIRY DATA PAGE (PAGE CODE C0h)
The Original Inquiry Data page is a vendor-specific Inquiry Data page. It
returns the Standard Inquiry Data for the tape drive as it was originally
specified in the firmware. The page is formatted as shown on page 4-3. All of
the Standard Inquiry Data that has been changed using the SEND
DIAGNOSTIC Set Inquiry Data command (86h) is replaced by the original
values.
4-10
SCSI REFERENCE
1009566-001
4.4 EXCEPTIONS AND ERROR CONDITIONS
4.4
EXCEPTIONS AND ERROR CONDITIONS
The tape drive returns Good status in response to an INQUIRY command,
even if it is not ready to accept commands. If the tape drive receives an
INQUIRY command from an initiator that has a pending Unit Attention
condition, the tape drive responds to the command and does not clear the
Unit Attention condition.
Table 4-2 lists exceptions and error conditions that cause the tape drive to
return Check Condition status for the INQUIRY command.
Table 4-2 REQUEST SENSE data for INQUIRY command errors and exceptions
Sense
Key
ASC
ASCQ
Explanation
(Byte 12) (Byte 13)
05h
OCTOBER 2008
24h
00h
Illegal Request. Invalid field in the CDB.
VXA-2 TAPE DRIVE
4-11
CHAPTER 4 INQUIRY (12h)
Notes
4-12
SCSI REFERENCE
1009566-001
5
LOAD/UNLOAD (1Bh)
Bit
Byte
00
7
6
5
4
3
2
1
0
0
0
0
1
1
0
1
1
Logical Unit Number
01
02
Immed
Reserved
03
Reserved
04
EOT
Re-Ten
Load
Control
05
5.1
Reserved
ABOUT THIS COMMAND
The LOAD/UNLOAD command causes the tape drive to load or unload the
data cartridge.
During a load operation, the tape drive performs the following actions:
1. It loads the tape into the tape path. (If the tape is already loaded, the tape
drive takes no action.)
Note:
The cartridge must be fully inserted into the tape drive when you
issue the LOAD command. The LOAD command does not pull the
cartridge into the tape drive.
2. It reads the logical format record at the beginning of the tape or determines
that the tape is blank.
3. It positions the tape at the logical beginning of partition 0 (LBOP).
4. It goes to the tape ready, idle state (LED 2 is on).
5. The tape drive returns Check Condition status with the sense key set to
Unit Attention (6h) to all initiators on the bus.
OCTOBER 2008
VXA-2 TAPE DRIVE
5-1
CHAPTER 5 LOAD/UNLOAD (1Bh)
When the tape drive receives tape motion commands during a load operation,
it queues (holds) one tape motion command per initiator (and disconnects, if
allowed) until the load operation is complete. Then it attempts to execute the
queued command.
Note: If another initiator has reserved the tape drive for its exclusive use, the tape
drive returns Reservation Conflict status to the initiator issuing the current
LOAD/UNLOAD command.
During an unload operation, the tape drive performs the following actions:
1. It completes any command or operation in progress.
2. If necessary, it writes any buffered information to tape, then writes an EOD
mark to indicate the end of data.
3. It writes the updated logical format record at the beginning of the tape.
4. It rewinds the tape to the physical beginning of tape (PBOT) and unloads
the tape from the tape path.
5. If the Prevent bit in the PREVENT MEDIUM REMOVAL command is not
set to 1 (see Chapter 11), it ejects the data cartridge.
6. After completing the unload operation, the tape drive returns Check
Condition status with the sense key set to Not Ready (2h) to all subsequent
commands that require tape motion.
5.2
CDB FIELD DEFINITIONS
Logical Unit Number (LUN) – Byte 01, Bits 7 through 5
The tape drive only supports LUN 0. The value for this field must be 0.
Byte 01, Bit 1 – Immed
This field specifies when the tape drive returns command status to the
initiator:
5-2
SCSI REFERENCE
0
Status is reported when the load/unload operation is
complete
1
Status is reported when the command is initiated by the
tape drive
1009566-001
5.2 CDB FIELD DEFINITIONS
If the buffer contains data from a previous WRITE command, the tape drive
does not execute the command until the data in the buffer is written to the
tape and an EOD mark appended. The tape drive then performs the load or
unload operation as follows:
If the Immed bit is set to... The tape drive returns...
1
Good status when the write operation has been
completed successfully. It then performs the
load or unload operation
0
status when the load or unload operation is
complete
If an error occurs during the writing of the data from the buffer to the tape, the
tape drive returns Check Condition status. The load or unload operation is not
performed.
Byte 04, Bit 2 – EOT
The tape drive ignores this bit.
Byte 04, Bit 1 – Re-Ten
The tape drive ignores this bit.
Byte 04, Bit 0 – Load
This field specifies which operation, load or unload, is to be performed:
0
Perform an unload operation
1
Perform a load operation
Table 5-1 indicates what action occurs based on the setting of the Load bit and
the status of the data cartridge.
Table 5-1 Action occurring based on the Load bit and data cartridge status
If the Load bit
is set to...
And the data
cartridge is...
0
Out
No action.
1
Out
Check Condition status is returned with the sense key set to Not Ready
(2h).
OCTOBER 2008
The following action occurs...
VXA-2 TAPE DRIVE
5-3
CHAPTER 5 LOAD/UNLOAD (1Bh)
Table 5-1 Action occurring based on the Load bit and data cartridge status (continued)
If the Load bit
is set to...
And the data
cartridge is...
0
1
a
The following action occurs...
In
The data cartridge is unloaded.a
If there is data in the write buffer, the data is written to tape. Then, the
tape is rewound to PBOT and unloaded from the tape path, and the
data cartridge is ejected from the tape drive.
In
The data cartridge is loaded and positioned at LBOP for partition 0.
If the data cartridge is already loaded and there is data in the buffer,
the data is written to the tape before the operation is performed.
The unload operation is performed even if the PREVENT/ALLOW MEDIUM REMOVAL command was issued
with the Prevent bit set to 1; however, the data cartridge is not ejected from the tape drive.
5.3
EXCEPTIONS AND ERROR CONDITIONS
Table 5-2 lists exceptions and error conditions that cause the tape drive to
return Check Condition status for the LOAD/UNLOAD command.
Table 5-2 REQUEST SENSE data for LOAD/UNLOAD command errors and exceptions
Sense
Key
ASC
ASCQ
Explanation
(Byte 12) (Byte 13)
02h
04h
01h
Not Ready. Tape drive is not ready, but is in process of becoming
ready (rewinding or loading tape).
02h
04h
02h
Not Ready. Tape drive is not ready because it is in the process of
ejecting a cartridge.
02h
04h
03h
Not Ready. The tape drive is not ready because it needs manual
intervention.
02h
3Ah
00h
Not Ready. Tape drive is not ready. Command requires a tape, and no
tape is present.
03h
30h
02h
Medium Error. The tape format is incompatible with the tape drive
hardware or microcode.
03h
31h
01h
Medium Error. The tape format is corrupted.
03h
50h
00h
Medium Error. The tape drive could not locate a valid splice location
on the tape. The tape is not located at a valid write position or the tape
drive could not locate the valid write position.
04h
15h
01h
Hardware Error. The tape drive cannot position the tape correctly.
04h
53h
00h
Hardware Error. The load or eject operation failed.
04h
53h
01h
Hardware Error. The unload operation failed.
05h
24h
00h
Illegal Request. Invalid field in the CDB.
06h
30h
00h
Unit Attention. Incompatible media was rejected after the cartridge
was inserted.
5-4
SCSI REFERENCE
1009566-001
6
LOCATE (2Bh)
Bit
Byte
00
7
6
5
4
3
2
1
0
0
0
1
0
1
0
1
1
BT
CP
Immed
Logical Unit Number
01
Reserved
02
03
Reserved
(MSB)
...
Block Address
(LSB)
06
07
Reserved
08
Partition
09
Control
6.1
ABOUT THIS COMMAND
The LOCATE command, in conjunction with the READ POSITION (34h)
command, allows you to position the tape at a specified logical block address.
During forward and backward locate operations, the tape drive moves the
tape at its highest speed.
Unlike space operations, locate operations do not detect filemarks and
setmarks and do not return Check Condition status when these elements are
encountered.
6.2
USING THE LOCATE COMMAND
To use the LOCATE command, follow these steps:
1. Determine the tape drive’s current location by issuing a READ POSITION
command (see Chapter 15).
2. In the initiator’s memory, save the information returned for the First Block
Location field (bytes 04 through 07) of the READ POSITION data.
3. Continue reading or writing data as required.
OCTOBER 2008
VXA-2 TAPE DRIVE
6-1
CHAPTER 6 LOCATE (2Bh)
4. When you want to return to the previous location, issue a LOCATE
command and specify the saved address in the Block Address field (bytes
03 through 06).
Note: If the tape drive receives a LOCATE command after a WRITE (0Ah) or
WRITE FILEMARKS (10h) command, it writes any buffered data, filemarks,
or setmarks to the tape before performing the locate operation.
If an error occurs while the buffered data is being written, the tape drive
returns Check Condition status and the locate operation is not performed.
Using the LOCATE Command on Partitioned Tapes
If the tape in the tape drive is formatted with partitions, you can use the
LOCATE command to position the tape to a location within any partition. If
necessary, the LOCATE command causes the tape drive to move from the
current partition to another partition and then to find the requested block in
the new partition. (See Section 2.6 starting on page 2-5 for information about
creating and using partitioned tapes.)
6.3
CDB FIELD DEFINITIONS
Logical Unit Number (LUN) – Byte 01, Bits 7 through 5
The tape drive only supports LUN 0. The value for this field must be 0.
Byte 01, Bit 2 – BT (Block Type)
This bit determines the type of block number the tape drive returns to the
initiator. The tape drive ignores this field.
Byte 01, Bit 1 – CP (Change Partitions)
This field specifies whether the tape drive should move to the partition
specified by the Partition field (byte 08) before positioning to the requested
block, as follows:
0
Ignore the Partition field
(Do not move the tape from the current partition.)
1
Move to the partition specified in the Partition field
Byte 01, Bit 0 – Immed
This field specifies when the tape drive returns command status to the
initiator, as follows:
6-2
SCSI REFERENCE
0
Status is reported when the LOCATE command is
completed
1
Status is reported when the LOCATE command is initiated
by the tape drive
1009566-001
6.4 EXCEPTIONS AND ERROR CONDITIONS
If the buffer contains data from a previous WRITE command, the tape drive
does not execute the LOCATE command until the data in the buffer is written
to the tape and an EOD mark is appended. The tape drive then performs the
erase operation as follows:
If the Immed bit is set to 1, the tape drive returns Good status and performs
the locate operation.
If the Immed bit is set to 0, the tape drive returns status when the locate
operation is complete.
Bytes 03 through 06 – Block Address
This field specifies the address of the block that the tape drive is to locate. The
value for this field is returned in the First Block Address field in the READ
POSITION data. Setting the Block Address to 0 causes the tape drive to
position the tape at LBOP.
Byte 08 – Partition
This field specifies to which partition the tape drive moves the tape when the
CP field (byte 01, bit 1) is set to 1 (change partitions), as follows:
n – Move to partition n, where n is either 0 or 1. Note that partitions are
numbered consecutively from the end of the tape. Partition 0 is always the
last partition on the tape.
The CP field must be set to 1 for the Partition byte to be in effect. If the CP field
is 0, the tape drive ignores the Partition byte.
6.4
EXCEPTIONS AND ERROR CONDITIONS
Table 6-1 lists exceptions and error conditions that cause the tape drive to
return Check Condition status for the LOCATE command.
Table 6-1 REQUEST SENSE data for LOCATE command errors and exceptions
Sense
Key
ASC
ASCQ
Explanation
(Byte 12) (Byte 13)
02h
04h
01h
Not Ready. Tape drive is not ready, but is in process of becoming
ready (rewinding or loading tape).
02h
04h
03h
Not Ready. The tape drive is not ready because it needs manual
intervention.
02h
3Ah
00h
Not Ready. Tape drive is not ready. Command requires a tape, and no
tape is present.
02h
Medium Error. The tape drive encounters the physical end of tape
(PEOT) or the physical end of partition (PEOP) before completing the
operation. When the LOCATE command terminates, the logical
position is the last logical position the tape drive detected on tape.
03h
OCTOBER 2008
00h
VXA-2 TAPE DRIVE
6-3
CHAPTER 6 LOCATE (2Bh)
Table 6-1 REQUEST SENSE data for LOCATE command errors and exceptions (continued)
Sense
Key
ASC
ASCQ
Explanation
(Byte 12) (Byte 13)
03h
14h
00h
Medium Error. The tape drive cannot perform the locate operation
because it cannot read data from the tape.
03h
30h
02h
Medium Error. The tape format is incompatible with the tape drive
hardware or microcode.
03h
31h
01h
Medium Error. The tape format is corrupted.
04h
15h
01h
Hardware Error. The tape drive cannot position the media correctly.
05h
24h
00h
Illegal Request. Invalid field in the CDB. This error is a result of any
of the following:
ƒ The Partition field contains a value greater than 1 and the CP bit is
set to 1.
ƒ The BT bit is set to 1.
06h
30h
00h
Unit Attention. Incompatible media was rejected after the cartridge
was inserted.
05h
Blank Check. The tape drive encountered an EOD mark. When the
LOCATE command terminates, the logical tape position is after the last
recorded data block, filemark, or setmark. Issue a READ POSITION
command to determine the exact location.
08h
6-4
00h
SCSI REFERENCE
1009566-001
7
LOG SELECT (4Ch)
Bit
Byte
00
7
6
5
4
3
2
1
0
0
1
0
0
1
1
0
0
PCR
SP
Logical Unit Number
01
Reserved
PC
02
Reserved
03
…
Reserved
06
07
(MSB)
Parameter List Length
08
Control
09
7.1
(LSB)
ABOUT THIS COMMAND
The LOG SELECT command allows you to manage the statistical information
maintained by the tape drive, including parameter values for write and read
error recovery operations and the amounts of data compressed. You can set
threshold and cumulative values and you can reset the values.
To test the tape drive, you can reset the parameters, perform the operations
you want to test, then issue a LOG SENSE (4Dh) command to check the
updated values (refer to Chapter 8 for information about the LOG SENSE
command).
You can also specify if and when you want to be notified about changes to the
parameters. For example, you might want the tape drive to return Unit
Attention when a counter reaches its threshold value.
!
OCTOBER 2008
Important
If you want the tape drive to return Unit Attention to notify you about
changes to the parameters, first issue a MODE SELECT command and
send the Control Mode page (Page Code=0Ah) with the Report Log
Exception Condition (RLEC) bit set to 1. Refer to Chapter 9 for more
information.
VXA-2 TAPE DRIVE
7-1
CHAPTER 7 LOG SELECT (4Ch)
7.2
CDB FIELD DEFINITIONS
Logical Unit Number (LUN) – Byte 01, Bits 7 through 5
The tape drive only supports LUN 0. The value for this field must be 0.
Byte 01, Bit 1 – PCR (Parameter Code Reset)
This field specifies whether the tape drive should reset all of the parameters or
only selected parameters, as follows:
0
Reset only selected parameters, as indicated by the PC
field
1
Reset all of the parameters
Current cumulative values will be reset to 0, the Enable
Threshold Comparison (ETC) bit will be reset to 0 (see
page 7-6), and threshold values will be reset to all FFs
Note: If you set the PCR bit to 1, be sure that the Parameter List Length is 0.
Otherwise, the tape drive returns Check Condition status with the sense
key set to Illegal Request (5h), the ASC and ASCQ set to 24h and 00h, and
the Fault Symptom Code set to 48h.
Byte 01, Bit 0 – SP (Save Parameters)
The tape drive does not support the save parameters function. The value for
this bit must be 0.
Byte 02, Bits 7 and 6 – PC (Page Control)
This field specifies which parameters the tape drive resets when the PCR bit
is 0. Table 7-1 lists the valid values for the PC field.
If the PCR bit is set to 1, the tape drive ignores the PC bit.
Table 7-1 Valid values for the LOG SELECT Page Control (PC) field
PC
Value
Description
00b
Set threshold values for the parameters listed in the parameter list.
01b
Set current cumulative values for the parameters listed in the parameter
list.
10b
Set all threshold values to their default threshold values (all FFs). Set the
ETC bit to 0 (see page 7-6).
11b
Set all current cumulative values to 0.
Note: If you set the PC field to 10b or 11b, be sure that the Parameter List Length
is 0. Otherwise, the tape drive returns Check Condition status with the
sense key set to Illegal Request (5h), the ASC and ASCQ set to 24h and
7-2
SCSI REFERENCE
1009566-001
7.2 CDB FIELD DEFINITIONS
00h, and the Fault Symptom Code set to 48h.
Bytes 07 and 08 – Parameter List Length
This field specifies the total number of bytes to be transferred to the tape drive.
The value for this field must equal the sum of the lengths of each log
parameter page being sent, including four bytes for each Parameter List
Header. Table 7-2 lists the page length, including the Parameter List Header,
for each supported log page.
Table 7-2 Page length of each supported log page
Page
Code
Description
Page Length
02h
Write Error Counters page
2Ch (44 bytes)
03h
Read Error Counters page
2Ch (44 bytes)
30h
Compression Statistics page
64h (100 bytes)
Multiple log parameter pages can be transferred with a single LOG SELECT
command. The parameter list length must be sufficient to accommodate all of
the log parameter pages being sent. The tape drive does not accept partial log
parameter pages.
Valid values for this field are 0 to FFFFh. Setting the Parameter List Length to 0
indicates that no data is to be transferred.
Note: If the Parameter List Length is greater than 0, the PCR bit must be 0.
Otherwise, the tape drive returns Check Condition status with the sense
key set to Illegal Request (5h), with the ASC and ASCQ set to 24h and 00h,
and the Fault Symptom Code set to 48h.
Table 7-3 summarizes the valid settings for the PCR, PC, and Parameter List
Length fields in the LOG SELECT CDB.
Table 7-3 Valid combinations of values for the fields in the LOG SELECT CDB
To specify these parameters values...
Set the
PCR
bit to...
Set the PC
field to...
Set the Parameter List
Length to...
Specified parameters to new threshold values
0
00b
Specified parameters to new cumulative values
0
01b
The total number of bytes in
the parameter lists for all of
the specified pages
All parameters to default threshold values (do
not reset cumulative values)
0
10b
All parameters to default cumulative values (do
not reset threshold values)
0
11b
All cumulative parameters to 0, all thresholds to
FFs, and ETC to 0
1
Ignored
OCTOBER 2008
0
VXA-2 TAPE DRIVE
7-3
CHAPTER 7 LOG SELECT (4Ch)
7.3
LOG PARAMETER DATA
With each LOG SELECT CDB, you send a parameter list for each page on
which you are changing values. Each parameter list begins with a Parameter
List Header that identifies the parameter page being sent and indicates the
number of bytes that follow the header as log parameters. Immediately
following the Parameter List Header is the list of values for each parameter on
the page that you want to change.
Note: The total number of bytes in the parameter list equals the Page Length of
the parameter page, plus four bytes for the Parameter List Header. The
sum of the bytes in all the parameter lists must equal the value specified
for the Parameter List Length in the CDB.
7.3.1
PARAMETER LIST HEADER
Each parameter list page begins with a four-byte Parameter List Header. The
Parameter List Header is followed by the parameters for the specified page.
Bit
Byte
7
6
5
3
Reserved
00
2
1
0
Page Code
Reserved
01
02
4
(MSB)
Page Length
03
(LSB)
Byte 00, Bits 5 through 0 – Page Code
This field specifies the page code for the parameter page to be modified. Valid
page codes are the following:
02h
Write Error Counters page
03h
Read Error Counters page
Notes:
Do not specify page codes 00h (Supported Log Pages page), 2Eh (TapeAlert
page), 31h (Tape Capacity page), 36h (Environmental Counter page), 37h (Tape
Usage page), or 39h (Tape Last FSC page) in the LOG SELECT command.
Although these page codes are valid for the LOG SENSE command, you cannot
change or reset the parameters on these pages using the LOG SELECT
command.
If you specify an invalid page code, the tape drive returns Check Condition
status with the sense key set to Illegal Request (5h), with the ASC and ASCQ set
to 24h and 00h, and the Fault Symptom Code set to 48h.
7-4
SCSI REFERENCE
1009566-001
7.3 LOG PARAMETER DATA
Bytes 02 and 03 – Page Length
This field indicates the number of bytes of log parameters that follow this field.
Table 7-2 lists the valid value of this field for each supported log page.
Table 7-4 Page length of each supported log page
Page
Code
Description
Page Length
02h
Write Error Counters page
28h (40 bytes)
03h
Read Error Counters page
28h (40 bytes)
7.3.2
LOG PARAMETERS
The Parameter List Header is followed by zero or more log parameters. Each
log parameter includes four bytes of descriptive information followed by a
variable-length parameter value. There is no required order for the log
parameters.
The general format of a log parameter is as follows:
Bit
Byte
00
7
6
5
(MSB)
DU
2
1
DS
TSD
ETC
0
(LSB)
TMC
RSVD
LP
Parameter Length
03
(MSB)
…
04
3
Parameter Code
01
02
4
Parameter Value
(LSB)
nn
Bytes 00 and 01 – Parameter Code
This field specifies the parameter for which you want to set the threshold or
cumulative value. The definition of the parameter depends on which log
parameter page you specified in the Parameter List Header.
OCTOBER 2008
VXA-2 TAPE DRIVE
7-5
CHAPTER 7 LOG SELECT (4Ch)
Table 7-5 lists the parameter codes and default values for the Write Error
Counters page (02h) and Read Error Counters page (03h). Section 8.3.3 on
page 8-8, provides a description of each parameter code.
Table 7-5 Parameter Codes and default values for the Write Error and Read Error Counters pages
Parameter Parameter Name
Code
Length Default
Default
Maximum Value
(bytes) Cumulative Value Threshold Value
0002h
Total Rewrites or Total
Rereads
4
0003h
Total Errors Corrected
(write or read)
4
0004h
Total Times Errors
Processed (write or read)
4
0005h
Total Bytes Processed
(write or read)
6
0006h
Total Unrecoverable
Errors (write or read)
2
00000000h
0FFFFFFFh
0FFFFFFFFh
00000000h
0FFFFFFFh
0FFFFFFFFh
00000000h
0FFFFFFFh
0FFFFFFFFh
000000000000h
0FFFFFFFFFFFh
0FFFFFFFFFFFFh
0000h
0FFFh
0FFFh
Byte 02, Bit 7 – DU (Disable Update)
This bit indicates whether updates to the current cumulative value are enabled
or disabled, as follows:
0
The tape drive can update the current cumulative value, so
comparisons of the current cumulative value and the
threshold value can occur normally.
1
The tape drive will not update the current cumulative
value, so threshold conditions will not be met for this
parameter.
Byte 02, Bit 6 – DS (Disable Save)
The tape drive ignores this bit.
Byte 02, Bit 5 – TSD (Target Save Disable)
The tape drive ignores this bit.
Byte 02, Bit 4 – ETC (Enable Threshold Comparison)
This bit indicates whether threshold comparisons for the parameter are
enabled or disabled, as follows:
7-6
SCSI REFERENCE
0
Threshold comparisons for this parameter are disabled.
1
Threshold comparisons are performed on this parameter.
1009566-001
7.3 LOG PARAMETER DATA
!
Important
If you want the tape drive to compare the current cumulative value to
the threshold value for the parameter and to return Unit Attention
when the threshold criteria are met, first issue a MODE SELECT
command and send the Control Mode page (Page Code=0Ah) with
the RLEC bit set to 1. Then, set the DU bit to 0 and the ETC bit to 1.
Byte 02, Bits 3 and 2 – TMC (Threshold Met Criteria)
This field specifies the conditions under which the tape drive generates a Unit
Attention (6h) sense key when comparing the current cumulative value to the
threshold value. Threshold comparisons are made when the cumulative value
is updated. Table 7-6 lists the valid values for the TMC field.
Table 7-6 Valid values for the LOG SELECT Threshold Met Criteria (TMC) field
TMC
Value
Description
00b
Return Unit Attention when the cumulative value is updated
01b
Return Unit Attention when the updated cumulative value equals the threshold value
10b
Return Unit Attention when the updated cumulative value is not equal to the threshold value
11b
Return Unit Attention when the updated cumulative value is greater than the threshold value
If threshold comparisons are enabled (DU=0 and ETC=1), the tape drive
compares the cumulative value to the threshold value when the cumulative
value is updated. When the conditions specified by the Threshold Met Criteria
(TMC) bit are met, the tape drive returns Check Condition status with the
sense key set to Unit Attention (6h), the ASC and ASCQ set to 5Bh and 01h,
respectively.
Byte 02, Bit 0 – LP (List Parameter)
The value for this field must be 0. (List parameters are not supported.)
Byte 03 – Parameter Length
This field specifies the length of the threshold or cumulative value in bytes.
See Table 7-5 for the length of each parameter on the supported log pages.
Note: You can specify any value from 0 to FFh for the Parameter Length field. If
you specify 0 for the Parameter Length, the Parameter Value will be set
to 0.
Bytes 04 to nn – Parameter Value
This field contains either a new threshold value or a new current cumulative
value for the parameter, depending on the value specified for the PC bit in the
CDB. The length of the value is defined by the Parameter Length field. See
Table 7-5 for the valid values for each parameter.
OCTOBER 2008
VXA-2 TAPE DRIVE
7-7
CHAPTER 7 LOG SELECT (4Ch)
If the specified parameter value is shorter than the actual length, the tape
drive pads the value with zeros from the parameter length to the most
significant byte. That is, if you specify 8h for the parameter value and the
length is two bytes, the tape drive pads the value to 0008h.
If the specified parameter value is longer than the actual length, all extra
bytes between the actual length and the most significant byte of the
Parameter Value must be 0. That is, if the length is two bytes, specifying
FFFFFFh for the value would be an error, specifying 00FFFFh would not.
7.4
EXCEPTIONS AND ERROR CONDITIONS
Table 7-7 lists the exceptions and error conditions that cause the tape drive to
return Check Condition status for the LOG SELECT command.
Table 7-7 REQUEST SENSE data for LOG SELECT command errors and exceptions
Sense
Key
ASC
ASCQ Explanation
(Byte 12) (Byte 13)
1h
5Bh
02h
Recovered Error. Log parameter overflow (a cumulative parameter
reached its maximum value). When this occurs, the parameter stays at
its maximum, and the DU bit is set to 1 to disable updates, and the tape
drive returns this error.
This error indicates that the tape drive completed the command with
no error. Check Condition status is returned only to alert the initiator
that a parameter reached its maximum.
5h
1Ah
00h
Illegal Request. Parameter List Length Error. The value specified for the
Parameter List Length caused the log parameter to be truncated.
00h
Illegal Request. Invalid field in CDB. This error is a result of any of the
following:
ƒ The PCR bit is set to 1 and the Parameter List Length is greater than 0.
ƒ The SP bit is set to 1.
ƒ The PC field is either 10b or 11b and the Parameter List Length is not
0.
5h
24h
5h
26h
00h
Illegal Request. Invalid field in parameter list. This error is a result of
any of the following:
ƒ An invalid or reserved Page Code or Parameter Code was specified.
ƒ The LP bit is set to 1.
6h
5Bh
01h
Unit Attention. Threshold met. (For additional information about this
error, look at the Log Parameter Page Code and Log Parameter Code
bytes in the REQUEST SENSE data.)
6h
2Ah
02h
Unit Attention. Log parameter changed.
0Bh
47h
00h
Aborted Command. A SCSI parity error occurred during data transfer.
7-8
SCSI REFERENCE
1009566-001
8
LOG SENSE (4Dh)
Bit
Byte
00
7
6
5
4
3
2
1
0
0
1
0
0
1
1
0
1
PPC
SP
Logical Unit Number
01
PC
02
03
(MSB)
Parameter Pointer
06
07
(MSB)
(LSB)
Allocation Length
08
(LSB)
Control
09
8.1
Page Code
Reserved
04
05
Reserved
ABOUT THIS COMMAND
The LOG SENSE command enables you to retrieve statistical information
about various tape drive parameter values. The tape drive maintains the
following pages of parameters:
Supported Pages page (00h)
Write Error Counters page (02h)
Read Error Counters page (03h)
TapeAlert page (2Eh)
Compression Statistics page (30h)
Tape Capacity page (31h)
Environmental Counter page (36h)
Tape Usage page (37h)
Tape Last FSC page (39h)
Drive Statistics Page (3C)
The LOG SENSE data returned by the tape drive consists of a four-byte
Parameter List Header and a log page. Each log page contains log parameter
data blocks that provide information about the parameters.
OCTOBER 2008
VXA-2 TAPE DRIVE
8-1
CHAPTER 8 LOG SENSE (4Dh)
Note: You can use the LOG SELECT (4Ch) command to specify cumulative and
threshold parameter values or to reset the parameters on pages 02h and
03h (see Chapter 7 for more information). You cannot set cumulative and
threshold values or reset the parameters on pages 31h, 36h, 37h, and 39h.
8.2
CDB FIELD DEFINITIONS
Logical Unit Number (LUN) – Byte 01, Bits 7 through 5
The tape drive only supports LUN 0. The value for this field must be 0.
Byte 01, Bit 1 – PPC (Parameter Pointer Control)
The PPC bit specifies the type of parameters being requested from the tape
drive. This bit must be 0, which indicates that the tape drive should return all
parameters for the specified log page, beginning with the parameter specified
in the Parameter Pointer field (bytes 05 and 06).
Byte 01, Bit 0 – SP (Save Parameters)
The tape drive does not support the save parameters function. The value for
this bit must be 0.
Byte 02, Bits 7 and 6 – PC (Page Control)
This field specifies the type of parameter values the tape drive returns.
Table 8-1 lists the valid values for the PC field.
Table 8-1 Valid values for the LOG SENSE Page Control (PC) field
PC Value
Description
00b
Return the current threshold values for the parameters listed in the parameter list. These
values are reset to their default settings after a power-on reset, SCSI bus reset, or Bus Device
Reset message.
01b
Return the current cumulative values for the parameters listed in the parameter list. These
values are the values that have accumulated since the last power-on reset, SCSI bus reset, Bus
Device Reset message, or setting by a LOG SELECT command. When a parameter reaches
its maximum value, it is returned as all FFs. (For example, FFFFFFFFh is returned as the
maximum value for a four-byte parameter.)
10b
Return the default threshold values. The default threshold values cannot be changed. The
values returned represent the maximum values each parameter can obtain (all FFs).
11b
Return the default cumulative values. The default cumulative values cannot be changed. The
values returned represent the values that each parameter is reset to (whether by power-on
reset, SCSI bus reset, Bus Device Reset message, or LOG SELECT reset). The default
cumulative value for all parameters is 0.
8-2
SCSI REFERENCE
1009566-001
8.2 CDB FIELD DEFINITIONS
Byte 02, Bits 5 through 0 – Page Code
This field specifies which LOG SENSE page is being requested. The type of
data returned for the page depends on the value specified for the PC bit.
Table 8-2 lists the log pages supported by the tape drive.
Table 8-2 Log pages supported by the tape drive
Page
Code
Description
Look here for
information....
00h
Supported Log Pages page. Return the lists of pages supported by the Section 8.3.2 on
LOG SENSE command.
page 8-8
02h
Write Error Counters page. Return log parameter data blocks for each Section 8.3.3 on
write error counter.
page 8-8
03h
Read Error Counters page. Return log parameter data blocks for each
read error counter.
2Eh
TapeAlert page. Return log parameter data blocks containing
Section 8.3.4 on
information from the tape drive’s internal TapeAlert firmware. This
page 8-9
firmware constantly monitors the tape drive and the tape for errors and
potential difficulties. When a problem is detected, the tape drive sets a
flag on this page to identify the type of problem detected.
30h
Compression Statistics page. Return log parameter data blocks for
containing the compression statistics.
Section 8.3.5 on
page 8-12
31h
Tape Capacity page. Return log parameter data containing statistics
about the partitions on the currently loaded data cartridge media.
Section 8.3.6 on
page 8-13
36h
Environmental Counter page. Return log parameter data blocks for
each environmental counter.
Section 8.3.7 on
page 8-13
37h
Tape Usage page. Return log parameter data blocks containing
statistics for the currently loaded tape.
Section 8.3.8 on
page 8-14
39h
Tape Last FSC page. Return log parameter data blocks containing
Section 8.3.9 on
statistics about the last five data cartridges loaded and unloaded in the page 8-16
tape drive.
3Ch
Drive Statistics page. Return log parameter data blocks containing
statistics about the last stored information regarding the counts
accumulated over the life of the tape drive.
Section 8.3.10 on
page 8-18
Bytes 05 and 06 – Parameter Pointer
This field specifies the Parameter Code of the first parameter to be returned for
the requested page. Valid values for this field are 00h through the highest
supported Parameter Code for the specified page. As long as the value in the
Allocation Length field is large enough, the tape drive returns all parameters
with a Parameter Code greater than or equal to the code specified in this field.
The parameters are returned in Parameter Code order (unsigned). If the
parameter specified does not exist, the tape drive returns the first available
parameter following the specified parameter.
OCTOBER 2008
VXA-2 TAPE DRIVE
8-3
CHAPTER 8 LOG SENSE (4Dh)
Notes:
If you set the Page Code field to 00h (Supported Log Pages page), the Parameter
Pointer field is ignored.
If the value for the Parameter Pointer is greater than the Parameter Code for any
of the parameters, the tape drive returns Check Condition status with the sense
key set to Illegal Request (5h), the ASC set to 24h, and the ASCQ set to 00.
Bytes 07 and 08 – Allocation Length
This field specifies the maximum number of bytes allocated by the initiator to
receive the data transferred by the tape drive. Valid values are from 0 to
FFFFh.
Table 8-3 lists the minimum Allocation Length required to return each
supported page. Each LOG SENSE command can return only one log page.
Note: It is not an error to specify a value for the Allocation Length field that
would truncate the information on one of the pages.
Table 8-3 Minimum Allocation Length required for each supported log page
Description
Minimum Allocation Lengtha
00h
Supported Log Pages page
0Dh (13 bytes)
02h
Write Error Counters page
2Ch (44 bytes)
03h
Read Error Counters page
2Ch (44 bytes)
2Eh
TapeAlert page
144h (324 bytes)
30h
Compression Statistics page
2Ch (44 bytes)
31h
Tape Capacity page
24h (36 bytes)
36h
Environmental Counter page
33h (53 bytes)
37h
Tape Usage page
FCh (252 bytes)
39h
Tape Last FSC page
72h (114 bytes)
3Ch
Drive Statistics page
0AEh (174 bytes)
Page Code
a
8.3
The minimum Allocation Length for each page includes the 4-byte Parameter List Header, a Log Parameter
Data Block for each parameter on the page, and the actual parameter values.
WHAT THE TAPE DRIVE RETURNS
This section describes the log page format and the log pages supported by the
tape drive. The LOG SENSE command returns the single log page specified in
the Page Code field of the CDB.
8-4
SCSI REFERENCE
1009566-001
8.3 WHAT THE TAPE DRIVE RETURNS
Each log page begins with a four-byte Parameter List Header (bytes 00 through
03), followed by zero or more variable-length log parameters defined for that
page. The Parameter List Header specifies the page code for the log parameter
data being returned and indicates the total length of the data to follow.
Bit
Byte
00
7
6
0
0
4
3
2
1
0
Page Code
Reserved
01
02
5
(MSB)
Page Length
03
(LSB)
Byte 00, Bits 5 through 0 – Page Code
This field identifies the type of LOG SENSE data being returned by the tape
drive. The value returned for this field matches the Page Code specified in the
CDB. Table 8-2 lists the log pages supported by the tape drive.
Bytes 02 and 03 – Page Length
This field indicates the total number of bytes that will follow this byte if the
Allocation Length specified in the CDB is sufficient. The value returned for
this field depends on the value specified for the Page Code and the Parameter
Pointer in the CDB. Table 8-3 lists the maximum Page Length of each
supported page.
8.3.1
LOG PARAMETER FORMAT
The tape drive returns the log parameters for the specified page immediately
after it returns the Parameter List Header. For each parameter on the page, the
tape drive returns a data block that includes four bytes of descriptive
information and a variable-length parameter value. The total number of bytes
returned for each parameter is equal to the value in the Parameter Length field
plus four bytes for the Parameter List Header.
The tape drive returns the log parameter data blocks for the specified LOG
SENSE page in Parameter Code order. The code for the first parameter will be
equal to or greater than the value specified for the Parameter Pointer field in
the CDB.
OCTOBER 2008
VXA-2 TAPE DRIVE
8-5
CHAPTER 8 LOG SENSE (4Dh)
Bit
Byte
00
7
6
5
4
(MSB)
DU
DS
TSD
1
0
ETC
(LSB)
TMC
RSVD
LP
Parameter Length
03
04
2
Parameter Code
01
02
3
(MSB)
…
Parameter Value
(LSB)
nn
Bytes 00 and 01 – Parameter Code
This field identifies the code of the parameter for which the tape drive is
returning a value. See the following sections for a list of the parameter codes
for each page.
Byte 02, Bit 7 – DU (Disable Update)
This field indicates whether updates to the current cumulative value for this
parameter are enabled or disabled, as follows:
0
The tape drive can update the current cumulative value, so
comparisons between the current cumulative value and
the threshold value occur normally.
1
The tape drive will not update the current cumulative
value, so threshold conditions will not be met for this
parameter.
Byte 02, Bit 6 – DS (Disable Save)
The tape drive always returns 1 for this bit, indicating that it does not support
the saving of log parameters.
Byte 02, Bit 5 – TSD (Target Save Disable)
The value for the Target Save Disable bit indicates whether the tape drive
provides a self-defined method for saving log parameters, as follows:
8-6
SCSI REFERENCE
0
The tape drive provides a self-defined method for saving
the current cumulative value for this counter. The counter
is not reset when the tape drive is reset.
1
The tape drive does not support saving the current
cumulative value for this counter. The counter is reset
when the tape drive is reset.
1009566-001
8.3 WHAT THE TAPE DRIVE RETURNS
Byte 02, Bit 4 – ETC (Enable Threshold Comparison)
This field indicates whether threshold comparisons are enabled or disabled for
this parameter:
0
Threshold comparisons are disabled for this parameter
1
Threshold comparisons are performed on this parameter
When threshold comparisons are enabled (and the DU bit is 0), the tape drive
compares the current cumulative value to the threshold value for the
parameter. When the conditions specified by the TMC bit are met, the tape
drive returns Check Condition status with the sense key set to Unit Attention
(6h), the ASC and ASCQ set to 5Bh and 01h.
Threshold comparisons are made when the cumulative value is updated.
Byte 02, Bits 3 and 2 – TMC (Threshold Met Criteria)
This field indicates the condition under which the tape drive generated the
Unit Attention (6h) sense key. Table 8-4 lists the valid values for the TMC field.
Table 8-4 Valid values for the LOG SENSE Threshold Met Criteria (TMC) field
TMC
Value
Description
00b
Unit Attention resulted when the cumulative value was updated
01b
Unit Attention resulted when the updated cumulative value equaled
the threshold value
10b
Unit Attention resulted when the updated cumulative value did not
equal to the threshold value
11b
Unit Attention resulted when the updated cumulative value was
greater than the threshold value
Note: If you want the tape drive to return Unit Attention to notify you about
changes to the parameters, first issue a MODE SELECT command and send
the Control Mode page (Page Code=0Ah) with the Report Log Exception
Condition (RLEC) bit set to 1. Refer to Chapter 9 for more information.
Byte 02, Bit 0 – LP (List Parameter)
The value for this bit is always 0, indicating that the tape drive does not
support List Parameters.
Byte 03 – Parameter Length
This field indicates the length of the threshold or cumulative value in bytes.
OCTOBER 2008
VXA-2 TAPE DRIVE
8-7
CHAPTER 8 LOG SENSE (4Dh)
Bytes 04 to nn – Parameter Value
This field contains either a threshold value or a cumulative value for the
parameter indicated by the Parameter Code field, depending on what you
specified for the PC bit in the CDB.
8.3.2
SUPPORTED LOG PAGES PAGE (PAGE CODE 00h)
The tape drive returns the Supported Log Pages page when the Page Code in
the CDB is 00h. The value in the Page Length field (bytes 2 and 3) of the
Parameter List Header for this page is 09h (9 bytes).
Unlike other LOG SENSE pages, no parameter information is returned on this
page. Instead, the Supported Log Pages page lists the page codes for the LOG
SENSE pages supported by the tape drive. The page codes are listed in
ascending order, as follows:
Bit
Byte
7
6
5
4
3
2
00
Supported Log Pages (00h)
01
Write Error Counters Page (Page Code 02h)
02
Read Error Counters Page (Page Code 03h)
03
TapeAlert Page (Page Code 2Eh)
04
Compression Statistics Page (Page Code 30h)
05
Tape Capacity Page (Page Code 31h)
06
Environmental Counter Page (Page Code 36h)
07
Tape Usage Page (Page Code 37h)
08
Tape Last FSC Page (Page Code 39h)
8.3.3
1
0
WRITE ERROR COUNTERS PAGE (PAGE CODE 02h)
READ ERROR COUNTERS PAGE (PAGE CODE 03h)
Setting the Page Code in the CDB to 02h (Write Error Counters page) or 03h
(Read Error Counters page) causes the tape drive to return the Write Error
Counters page or the Read Error Counters page, respectively. The value in the
Page Length field (bytes 2 and 3) of the Parameter List Header for either of
these pages is 28h (40 bytes).
8-8
SCSI REFERENCE
1009566-001
8.3 WHAT THE TAPE DRIVE RETURNS
Table 8-5 lists the parameters used to return information about the write or
read error on the Write Error Counters page and the Read Error Counters
page.
Table 8-5 Parameters returned on the LOG SENSE Write Error and Read Error Counters pages
Parameter
Code
Parameter
Name
Description
Length
(bytes)
Total
Rewrites
The number of physical blocks the tape drive rewrote because
they contained errors detected during check-after-write
operations.
4
Indicates the number of times the tape drive moved the tape
backward to reread a portion of tape because a block was
missed.
4
Write error. Contains the same value as the Total Rewrites
counter.
4
Read error. Indicates the total number of blocks the tape drive
recovered either by using the ECC algorithm or by successfully
rereading the block.
4
0002h
Total Rereads
0003h
0004h
0005h
0006h
Total Errors
Corrected
Write error. Always contains 0 since write errors are rewritten.
Total Times
Errors Processed Read error. The number of blocks corrected by ECC.
Total Bytes
Processed
Total
Unrecoverable
Errors
8.3.4
4
4
Write error. The number of bytes successfully written to the
tape. This counter only includes user data bytes. Rewritten data
is not counted.
6
Read error. The number of user bytes read from tape and
transferred to the initiator.
6
Write error. The number of times the tape drive could not write
a block to the tape after all retries.
2
Read error. The number of times a block could not be read
from tape after all retries.
2
TAPEALERT PAGE (PAGE CODE 2Eh)
The tape drive’s internal TapeAlert firmware constantly monitors the tape
drive and the tape for errors and potential difficulties. Any problems
identified are flagged on the TapeAlert page. There are two methods of
accessing this information:
If TapeAlert is enabled using the MODE SELECT command (see
Section 9.10), the tape drive returns a Recovered Error message to the
initiator on the next SCSI command whenever one or more TapeAlert flags
are set. A pending Recovered Error will be returned on the first successful
SCSI command after the TapeAlert flag is set. The TapeAlert log page should
be read immediately after the Recovered Error message is received.
OCTOBER 2008
VXA-2 TAPE DRIVE
8-9
CHAPTER 8 LOG SENSE (4Dh)
The command which receives the Recovered Error message will have
executed correctly and should not be reissued by the initiator.
Note:
The host software can periodically read the TapeAlert log page to determine
if any new flags have been set. If this method is used, the initiator should
read the log page whenever any of the following occur:
Immediately after a SCSI Check Condition status followed by a
REQUEST SENSE.
At the end of each tape when a job spans multiple tapes. If the data
cartridge will be ejected, then the TapeAlert page must be read before the
tape is unloaded.
At the completion of an operation.
Before a tape is unloaded.
At some regularly scheduled interval (for example, once a minute).
Setting the Page Code in the CDB to 2Eh causes the tape drive to return the
TapeAlert log page. The value in the Page Length field (bytes 2 and 3) of the
Parameter List Header for this page is 0140h (320 bytes).
Table 8-6 lists the TapeAlert flags on the TapeAlert page. Each TapeAlert flag
includes four bytes of descriptive information (see page<$pagenum>),
followed by a one-byte parameter value for the flag. Bit 0 of the parameter
value contains the value for the flag, as follows:
0
The flag is not currently set
1
The flag is currently set
The remaining 7 bits of the flag are not used.
Notes:
Issuing a LOG SENSE command to return the TapeAlert page resets all of the flags
to 0. The flags are also reset whenever the tape drive is reset or when the
condition indicated by the flag is corrected.
Although the tape drive only supports the TapeAlert flags listed in Table 8-6, it
returns all 64 flags defined in the TapeAlert standard. Unused flags are set to 0.
See page ii for information on how to contact Tandberg Data Technical Support.
8-10
SCSI REFERENCE
1009566-001
8.3 WHAT THE TAPE DRIVE RETURNS
Table 8-6 Parameters returned on the LOG SENSE TapeAlert page
Parameter
Flag name
Typea
Description
03h
Hard Error
W
A hard read/write error has occurred. The current operation has
stopped because the tape drive cannot correct an error that
occurred while the tape drive was reading or writing data.
C
Media performance is severely degraded. Your data is at risk. To
safeguard the data on this tape, do the following:
ƒ Copy any data you want to preserve to another tape.
ƒ Do not use this tape again.
Restart the current operation using a different tape.
C
The tape drive can no longer read data from the tape. Either the
tape is faulty or the tape drive is not operating correctly.
ƒ Try reading data from a known good tape. If you can read this
tape, replace the damaged tape.
ƒ If the problem persists, contact Technical Support.
04h
05h
Media
Read Failure
06h
Write Failure
C
The tape drive can no longer write data to the tape. Either the
tape is faulty or the tape drive is not operating correctly.
ƒ Try writing data to a known good tape. If you can write to this
tape, replace the faulty tape.
ƒ If the problem persists, contact Technical Support.
08h
Not Data Grade
W
The tape drive cannot read the MRS stripes on the tape. The tape
is not data-grade. Any data you back up onto the tape is at risk.
Replace the cartridge with one containing data-grade tape.
09h
Write Protect
C
The initiator attempted to write to a write-protected data
cartridge. Write-enable the cartridge or use another cartridge.
0Ah
No Removal
I
A data cartridge unload operation was attempted while the
initiator was preventing media removal.
0Bh
Cleaning Media
I
A cleaning cartridge is currently in the tape drive. If you want to
back up or restore, insert a data cartridge.
0Ch
Unsupported
Format
I
The loaded tape contains data in an unsupported format.
0Dh
Snapped Tape
C
The data cartridge in the tape drive contains a broken tape.
ƒ Discard the data cartridge.
ƒ Restart the current operation with a different tape.
10h
Forced Eject
C
The user ejected the cartridge while the tape drive was in the
process of reading or writing data.
12h
Tape Directory
Corrupted
W
The logical format of the tape has been corrupted, rendering the
tape unusable. Reformat the tape.
13h
Nearing Media
Life
I
The data cartridge currently in the tape drive is approaching the
end of its usable life.
OCTOBER 2008
VXA-2 TAPE DRIVE
8-11
CHAPTER 8 LOG SENSE (4Dh)
Table 8-6 Parameters returned on the LOG SENSE TapeAlert page (continued)
Parameter
Typea
Description
14h
Clean Now
C
The tape drive needs cleaning.
ƒ If the tape drive is not currently in use, eject any data cartridge
and insert a cleaning cartridge to clean the tape drive.
ƒ If the tape drive is in use, wait until the current operation is
complete, then insert a cleaning cartridge to clean the tape
drive.
15h
Clean Periodic
W
The tape drive needs to be cleaned at the next opportunity.
16h
Expired Cleaning
Media
C
The cleaning cartridge that was inserted into the tape drive is
used up. Use a new cleaning cartridge to clean the tape drive.
C
The tape drive has a problem that is not read/write related.
ƒ Turn the tape drive off and then on again.
ƒ Restart the operation.
ƒ If the problem persists, contact Technical Support.
1Fh
a
Flag name
Hardware B
20h
Interface
W
There is a problem in the SCSI interface between the initiator and
the tape drive.
ƒ Check all of the SCSI cables and connections.
ƒ Restart the operation.
22h
Download Fail
W
The last attempt to download new firmware has failed. Obtain
the correct firmware and try again.
24h
Drive
Temperature
W
The tape drive’s internal temperature at the tape path has
exceeded 47° C (117° F).
I = Informational suggestion to user.
W = Warning. Remedial action is advised. Performance of data may be at risk.
C = Critical. Immediate remedial action is required.
8.3.5
COMPRESSION STATISTICS (PAGE CODE 30h)
Setting the Page Code in the CDB to 30h causes the tape drive to return the
Compression Statistics log page. The value in the Page Length field (bytes 2
and 3) of the Parameter List Header for this page is 28h (40 bytes).
Table 8-7 lists the parameters used to provide cumulative compression
statistics for tape currently loaded in the tape drive.
Table 8-7 Parameters returned on the LOG SENSE Compression Statistics page
Parameter
Code
Parameter
Name
8000h
User Bytes Written
8001h
User Bytes Read
8-12
SCSI REFERENCE
Length
(bytes)
Description
The amount of data, in bytes, that was written to tape
(before compression).
6
The amount of data, in bytes, that was read from tape (after
decompression).
6
1009566-001
8.3 WHAT THE TAPE DRIVE RETURNS
Table 8-7 Parameters returned on the LOG SENSE Compression Statistics page (continued)
Parameter
Code
Parameter
Name
Description
Length
(bytes)
8002h
Compressed Bytes
Written
The amount of compressed data, in bytes, that was written
to tape.
6
8003h
Compressed Bytes
Read
The amount of compressed data, in bytes, that was read
from tape.
6
8.3.6
TAPE CAPACITY PAGE (PAGE CODE 31h)
Setting the Page Code in the CDB to 31h causes the tape drive to return the
Tape Capacity log page. The value in the Page Length field (bytes 2 and 3) of
the Parameter List Header for this page is 20h (32 bytes).
Table 8-8 lists the parameters used to provide capacity information about the
partitions on the tape currently loaded in the tape drive.
Table 8-8 Parameters returned on the LOG SENSE Tape Capacity page
Parameter
Code
Parameter
Name
Description
Length
(bytes)
1h
Partition 0 Remaining
The number of kilobytes of data that might be written
between the current location and the EOP for partition 0.
4
2h
Partition 1 Remaining
The number of kilobytes of data that might be written
between the current location and the EOP for partition 1.
4
3h
Partition 0 Maximum
The maximum number of kilobytes of data that might be
written in partition 0.
4
4h
Partition 1 Maximum
The maximum number of kilobytes of data that might be
written in partition 1.
4
8.3.7
ENVIRONMENTAL COUNTER PAGE (PAGE CODE 36h)
Setting the Page Code in the CDB to 36h causes the tape drive to return the
Environmental Counter log page. The value in the Page Length field (bytes 2
and 3) of the Parameter List Header for this page is 2Fh (47 bytes).
OCTOBER 2008
VXA-2 TAPE DRIVE
8-13
CHAPTER 8 LOG SENSE (4Dh)
Table 8-9 lists the parameters used to provide statistics about the operational
environment of the tape drive. If a counter reaches its maximum value, it will
remain at that value and not roll back to zero.
Table 8-9 Parameters returned on the LOG SENSE Environmental Counter page
Parameter
Code
Parameter
Name
8000h
Current
Temperature
The current temperature of the tape drive as measured at the
tape path.
1
8001h
Max
Temperature
The maximum temperature reached by the tape drive during
this power cycle.
1
8002h
Lifetime Max
Temperature
The maximum temperature reached by the tape drive during its
lifetime.
1
8003h
Min
Temperature
The minimum temperature reached by the tape drive during this
power cycle.
1
8002h
Lifetime Min
Temperature
The minimum temperature reached by the tape drive during its
lifetime.
1
8005h
Lifetime
Minutes
Tensioned
The number of minutes the drive has had tape tensioned in its
lifetime.
8006h
Minutes Since
Last Clean
The number of minutes the drive has had tape tensioned since
a cleaning cartridge was last used.
4
8007h
Lifetime Clean
The number of times a cleaning cartridge has been used on the
drive in its lifetime.
2
8.3.8
Length
(bytes)
Description
4
TAPE USAGE PAGE (PAGE CODE 37h)
Setting the Page Code in the CDB to 37h causes the tape drive to return the
Tape Usage page. The value in the Page Length field (bytes 2 and 3) of the
Parameter List Header for this page is F8h (248 bytes).
Table 8-10 lists the parameters used to provide usage statistics for the data
cartridge currently loaded in the tape drive. These statistics are stored on the
data cartridge and read by the tape drive when the cartridge is loaded.
Current values are the statistics kept since the cartridge was loaded. These
values are not included in the lifetime statistics.
Previous values are statistics from the last time the tape was loaded. These
values are included in the lifetime statistics.
Lifetime values are the cumulative statistics over the life of the data
cartridge.
If a counter reaches its maximum value, it will remain at that value and not
roll back to zero.
8-14
SCSI REFERENCE
1009566-001
8.3 WHAT THE TAPE DRIVE RETURNS
No data is available if the tape drive does not currently have a data cartridge
loaded. Tape drive returns Not Ready status with the ASC set to 3Ah and the
ASCQ set to 00h (Medium Not Present).
Table 8-10 Parameters returned on the LOG SENSE Tape Usage page
Parameter
Code
Parameter
Name
Description
Length
(bytes)
8000h
Current Bytes
Written
The number of bytes written since the data cartridge was loaded
as a multiple of 10000h.
4
8001h
Current Bytes
Read
The number of bytes read since the data cartridge was loaded
as a multiple of 10000h.
4
8002h
Current Rewrites
The number of bytes rewritten since the data cartridge was
loaded.
4
8003h
Current Rereads The number of bytes reread since the data cartridge was loaded.
2
8004h
Current Blocks
ECC Corrected
The number of blocks corrected using ECC since the data
cartridge was loaded.
4
8005h
Current Times
Device Pause
The number of times the tape drive paused since the data
cartridge was loaded. A pause results from one of the following
conditions:
ƒ During a write operation, the data buffer was empty.
ƒ During a read operation, the data buffer was full.
4
8006h
Current Rewinds
The number of times the tape has been rewound since the data
cartridge was loaded.
2
8007h
Current
Max/Min
Temperature
The current maximum and minimum temperature (1 byte each,
in degrees Celsius) reached by the tape drive since the data
cartridge was loaded.
2
8008h
Current Tape
Repartitions
The number of times the tape has been repartitioned since the
data cartridge was loaded.
2
8009h
Current Drive
Serial
The serial number of the tape drive in which the data cartridge
is currently loaded.
4
800Ah
Previous Bytes
Written
The number of bytes written the last time the data cartridge was
loaded as a multiple of 10000h.
4
800Bh
Previous Bytes
Read
The number of bytes read the last time the data cartridge was
loaded as a multiple of 10000h.
4
800Ch
Previous
Rewrites
The number of bytes rewritten the last time the data cartridge
was loaded.
4
800Dh
Previous
Rereads
The number of bytes reread the last time the data cartridge was
loaded.
2
800Eh
Previous Blocks
ECC Corrected
The number of blocks corrected using ECC the last time the data
cartridge was loaded.
4
800Fh
Previous Times
Device Pause
The number of times the tape drive was paused the last time the
data cartridge was loaded.
4
OCTOBER 2008
VXA-2 TAPE DRIVE
8-15
CHAPTER 8 LOG SENSE (4Dh)
Table 8-10 Parameters returned on the LOG SENSE Tape Usage page (continued)
Parameter
Code
Parameter
Name
8010h
Previous
Rewinds
8011h
Length
(bytes)
Description
The number of times the tape was rewound the last time the
data cartridge was loaded.
2
Previous
Max/Min
Temperature
The current maximum and minimum temperature (1 byte each,
in degrees Celsius) reached by the tape drive the last time the
data cartridge was loaded.
2
8012h
Current Tape
Repartitions
The number of times the tape was repartitioned the last time the
data cartridge was loaded.
2
8013h
Previous Drive
Serial
The serial number of the previous tape drive in which the data
cartridge was loaded.
4
8014h
Lifetime Bytes
Written
The number of bytes written over the lifetime of the cartridge as
a multiple of 10000h.
6
8015h
Lifetime Bytes
Read
The number of bytes read over the lifetime of the cartridge as a
multiple of 10000h.
6
8016h
Lifetime
Rewrites
The number of bytes rewritten over the lifetime of the cartridge.
8017h
Lifetime Rereads The number of bytes reread over the lifetime of the cartridge.
6
6
8018h
Lifetime Blocks
ECC Corrected
The number of blocks corrected using ECC over the lifetime of
the cartridge.
6
8019h
Lifetime Times
Device Pause
The number of times the tape drive paused over the lifetime of
the cartridge.
6
801Ah
Lifetime
Rewinds
The number of times the tape has been rewound over the
lifetime of the cartridge.
4
801Bh
Lifetime
Max/Min
Temperature
The current maximum and minimum temperature (1 byte each,
in degrees Celsius) reached by the tape drive over the lifetime
of the cartridge.
2
801Ch
Lifetime Tape
Repartitions
The number of times the tape has been repartitioned over the
lifetime of the cartridge.
2
801Dh
Lifetime Load
The number of times the cartridge has been loaded into a tape
drive over the lifetime of the cartridge.
4
801Eh
Initial Drive
Serial Number
The serial number of the first tape drive into which the data
cartridge was loaded.
4
801Fh
Tape Serial
Number
8.3.9
The serial number of the data cartridge.
4
TAPE LAST FSC PAGE (PAGE CODE 39h)
Setting the Page Code in the CDB to 39h causes the tape drive to return the
Tape Last FSC log page. The value in the Page Length field (bytes 2 and 3) of
the Parameter List Header for this page is 6Eh (110 bytes).
8-16
SCSI REFERENCE
1009566-001
8.3 WHAT THE TAPE DRIVE RETURNS
Table 8-11 lists the parameters used to provide statistics about the last five data
cartridges loaded (and unloaded) into the tape drive. The statistics for Tape 0
are for the least recent cartridge loaded; the statistics for Tape 4 are for the
most recent cartridge. If a data cartridge is currently loaded in the tape drive,
the information for that cartridge is not included in the statistics.
The tape drive stores these statistics in nonvolatile memory just before the
cartridge is unloaded. It reflects the ending status of the last motion command
(ERASE, LOCATE, READ, SPACE, or WRITE) executed before the unload
operation.
Table 8-11 Parameters returned on the LOG SENSE Tape Last FSC page
Parameter
Code
Parameter
Name
Description
Length
(bytes)
8000h
Tape 0 Last FSC
The last FSC (fault symptom code) posted for a motion
command by the tape drive while the least recent tape (tape
0) was loaded.
1
8001h
Tape 0 Last
Motion
Command
The last motion command executed by the tape drive while
tape 0 was loaded.
1
8002h
Tape 0 ID
The ID of tape 0.a
8
The last FSC (fault symptom code) posted for a motion
command by the tape drive while the second from last tape
(tape 1) was loaded.
1
8003h
Tape 1 Last FSC
8004h
Tape 1 Last
Motion
Command
The last motion command executed by the tape drive while
tape 1 was loaded.
1
8005h
Tape 1 ID
The ID of tape 1.
8
The last FSC (fault symptom code) posted for a motion
command by the tape drive while the third from last tape
(tape 2) was loaded.
1
8006h
Tape 2 Last FSC
8007h
Tape 2 Last
Motion
Command
The last motion command executed by the tape drive while
tape 2 was loaded.
1
8008h
Tape 2 ID
The ID of tape 2.
8
The last FSC (fault symptom code) posted for a motion
command by the tape drive while the fourth from last tape
(tape 3) was loaded.
1
8009h
Tape 3 Last FSC
800Ah
Tape 3 Last
Motion
Command
The last motion command executed by the tape drive while
tape 3 was loaded.
1
800Bh
Tape 3 ID
The ID of tape 3.
8
800Ch
Tape 4 Last FSC
The FSC (fault symptom code) posted for the tape drive while
the most recent tape (tape 4) was loaded.
1
OCTOBER 2008
VXA-2 TAPE DRIVE
8-17
CHAPTER 8 LOG SENSE (4Dh)
Table 8-11 Parameters returned on the LOG SENSE Tape Last FSC page (continued)
a
Parameter
Code
Parameter
Name
Length
(bytes)
800Dh
Tape 4 Last
Motion
Command
The last motion command executed by the tape drive while
tape 4 was loaded.
1
800Eh
Tape 4 ID
The ID of tape 4.
8
Description
The Tape ID is derived by concatenating the last eight digits of the serial number for the tape drive that first formatted the tape, followed
by an eight-digit hexadecimal number indicating the total number of tapes that have been formatted for the first time by the indicated
tape drive.
8.3.10
DRIVE STATISTICS PAGE (PAGE CODE 3Ch)
Setting the Page Code in the CDB to 3Ch allows you to access the information
regarding the counts accumulated over the life of the tape drive. This
information is the data last stored by the tape drive.
Table 8-12 contains statistics concerning the tape drive that were collected over
the lifetime of the device.
Table 8-12 Parameters returned on the LOG SENSE Drive Statistics page
Parameter
Code
Parameter
Name
0001h
Write Media
Blocks Counter
This is a lifetime statistic representing the number of physical
groups written during a write operation. When the counter
reaches the maximum value, it does not wrap back to zero,
but retains its maximum value (FFFFFFFFFFFFFFFFh).
8
0002h
Rewrite Media
Blocks Counter
This is a lifetime statistic representing the number of physical
groups rewritten during a write operation. When the counter
reaches the maximum value, it does not wrap back to zero,
but retains its maximum value (FFFFFFFFFFFFFFFFh).
8
Read Media Blocks This is a lifetime statistic representing the number of physical
Counter
groups read during a read or space operation. The counter
does not increment or decrement during a space reverse, a
space LEOP, or a space fast operation. When the counter
reaches the maximum value, it does not wrap back to zero,
but retains its maximum value (FFFFFFFFFFFFFFFFh).
8
0003h
Length
(bytes)
Description
0004h
ECC Corrections
Counter
This is a lifetime statistic representing the number of physical
groups corrected during a read operation. When the counter
reaches the maximum value, it does not wrap back to zero,
but retains its maximum value (FFFFFFFFFFFFFFFFh).
8
0005h
Reread Media
Blocks Counter
This is a lifetime statistic representing the number of physical
groups reread during a read operation. When the counter
reaches the maximum value, it does not wrap back to zero,
but retains its maximum value (FFFFFFFFFFFFFFFFh).
8
8-18
SCSI REFERENCE
1009566-001
8.3 WHAT THE TAPE DRIVE RETURNS
Table 8-12 Parameters returned on the LOG SENSE Drive Statistics page (continued)
Parameter
Code
Parameter
Name
Length
(bytes)
0006h
Cumulative
Cartridge Loads
Counter
This counter increments each time a new cartridge is loaded
(all media types and lengths except cleaning cartridges).
When the counter reaches the maximum value, it does not
wrap back to zero, but retains its maximum value (FFFFFFh).
3
0007h
Time Since Last
Cleaning Counter
This counter expresses (in minutes) the tape pulling time since
the last cleaning. When the counter reaches the maximum
value, it does not wrap back to zero, but retains its maximum
value (FFFFFFh). When the tape drive is cleaned, the counter
resets to zero.
3
0008h
Cumulative Power This counter expresses (in minutes) the cumulative count of
On Time Counter the time that the tape drive has been powered on. When the
counter reaches the maximum value, it does not wrap back to
zero, but retains its maximum value (FFFFFFh).
3
Description
0009h
Cumulative Tape
Tension
This counter expresses (in minutes) the cumulative count of
the time that the tape drive has had tape loaded and under
tension with the drum spinning. When the counter reaches
the maximum value, it does not wrap back to zero, but retains
its maximum value (FFFFFFh).
000Ah
Cumulative
Cleaning Counter
This is a lifetime statistic representing the number of times a
cleaning cartridge has been loaded into the drive. When the
counter reaches the maximum value, it does not wrap back to
zero, but retains its maximum value (FFFFh).
2
OEM Unique
2
000Ch
Media “Dead” Flag OEM Unique
2
000Dh
Drive “Dead” Flag OEM Unique
2
000Bh
Worn Tape Flag
3
000Eh
Undefined
NA
2
000Fh
Undefined
NA
2
0010h
Undefined
NA
2
0011h
Time to Clean Flag ƒ
ƒ
ƒ
ƒ
Valid is 0 — the Clean bit is not valid and should be ignored
Valid is 1 — the Clean bit is valid
Clean is 0 — Cleaning is not required
Clean is 1 — A cleaning cartridge should be used on this
tape drive as soon as possible
1
0012h
Undefined
NA
1
0013h
Undefined
NA
3
0014h
Undefined
NA
3
0015h
Cartridge Serial
Number
OCTOBER 2008
This lists the data cartridge serial number if it is available.
VXA-2 TAPE DRIVE
12
8-19
CHAPTER 8 LOG SENSE (4Dh)
8.4
EXCEPTIONS AND ERROR CONDITIONS
Table 8-13 lists the exceptions and error conditions that cause the tape drive to
return Check Condition status for the LOG SELECT command.
Table 8-13 REQUEST SENSE data for LOG SENSE command errors and exceptions
Sense
Key
02h
5h
8-20
ASC
ASCQ Explanation
(Byte 12) (Byte 13)
3Ah
24h
SCSI REFERENCE
00h
Not Ready. Tape drive is not ready. Command requires a tape, and no
tape is present.
00h
Illegal Request. Invalid field in CDB. This error is a result of any of the
following:
ƒ The PPC bit is not 0.
ƒ The SP bit is set to 1.
ƒ The Page Code field is not 00h, 02h, or 03h.
ƒ The Parameter Pointer is an invalid value greater than 06h.
1009566-001
9
MODE SELECT (15h)
Bit
Byte
7
6
5
4
3
2
1
0
00
0
0
0
1
0
1
0
1
Logical Unit Number
01
02
PF
Reserved
Reserved
03
04
Parameter List Length
05
Control
9.1
SP
ABOUT THIS COMMAND
The MODE SELECT command allows the initiator to specify medium and
device parameters. These parameters apply to all initiators in a multi-initiator
environment. The parameters transferred from the initiator after the CDB are
structured as pages of related parameters (SCSI-2 format). The parameters are
transferred in the following order:
Parameter List Header
Block Descriptor (optional)
One or more available pages of related parameters
Unless otherwise noted, the parameters set using this command return to
their default values whenever the tape drive is power-cycled or reset (SCSI bus
reset or Bus Device Reset).
9.2
CDB FIELD DEFINITIONS
Logical Unit Number (LUN) – Byte 01, Bits 7 through 5
The tape drive only supports LUN 0. The value for this field must be 0.
Byte 01, Bit 4 – PF (Page Format)
The tape drive ignores this field. All of the parameters use standard page format.
OCTOBER 2008
VXA-2 TAPE DRIVE
9-1
CHAPTER 9 MODE SELECT (15h)
Byte 01, Bit 0 – SP (Saved Page)
The tape drive does not support the saved page function. The valid value for
this bit is 0.
Byte 04 – Parameter List Length
This field indicates the total number of bytes to be transferred from the
initiator to the tape drive. All parameters after the Block Descriptor are
transferred as pages of parameters. There is no specific order for the parameter
pages.
To determine the Parameter List Length, total the number of bytes contained
in the Parameter List Header, the Block Descriptor (if you are sending it), and
all of the parameter pages you are sending. The maximum value you can
specify is FFh. Table 9-1 lists the lengths of the Parameter List Header, Block
Descriptor, and each supported mode page.
Note: When the value for the Parameter List Length is 0, no data is transferred
from the initiator. A value of 0 is not an error.
Table 9-1 MODE SELECT parameter page lengths
Parameter
Length
Parameter List Header
04h (4 bytes)
Block Descriptor
08h (8 bytes)
Read-Write Recovery page (Page Code 01h)
0Ch (12 bytes)
Disconnect-Reconnect page (Page Code 02h)
10h (16 bytes)
Control Mode page (Page Code 0Ah)
08h (8 bytes)
Data Compression page (Page Code 0Fh)
10h (16 bytes)
Device Configuration page (Page Code 10h)
10h (16 bytes)
Medium Partition page (Page Code 11h)
88h (136 bytes)
TapeAlert page (Page Code 1Ch)
0Ch (12 bytes)
Vendor Unique Parameters Page 1 (Page Code 21h)
06h (6 bytes)
Restrictions for sending MODE SELECT parameters:
For data transfers greater than 0 bytes, the entire Parameter List Header
must be transferred before the Block Descriptor or any parameter page or
vendor-unique parameters.
The Parameter List Header, Block Descriptor, and any parameter pages must
be transferred in their entirety; partial transfers of these data segments are
not allowed.
9-2
SCSI REFERENCE
1009566-001
9.3 MODE PARAMETER DATA
Note:
9.3
Any value for the Parameter List Length that causes the Parameter List
Header, Block Descriptor, or one of the parameter pages to be
truncated will terminate the command with Check Condition status.
The sense key will be set to Illegal Request and the Additional Sense
Code will be set to Parameter List Length Error.
MODE PARAMETER DATA
With each MODE SELECT CDB, you send a parameter list for each page on
which you are changing values. Each parameter list begins with a Parameter
List Header that identifies the parameter page being sent and indicates the
number of bytes that follow the header as mode parameters. Immediately
following the Parameter List Header is an optional Block Descriptor, followed
by the list of values for each parameter on the page that you want to change.
Note: The total number of bytes in the parameter list equals the Page Length of
the parameter page, plus four bytes for the Parameter List Header. The
sum of the bytes in all the parameter lists must equal the value specified
for the Parameter List Length in the CDB.
9.3.1
PARAMETER LIST HEADER
Each parameter list page begins with a four-byte Parameter List Header. The
Parameter List Header is followed by the parameters for the specified page.
Bit
Byte
7
6
5
4
00
2
1
0
Reserved
01
02
3
RSVD
Buffered Mode
Speed
Block Descriptor Length
03
Byte 02, Bits 6 through 4 – Buffered Mode
This field specifies the data transfer mode to be used by the tape drive. The
tape drive supports two data transfer modes:
000b
Unbuffered mode
001b
Buffered mode (power-on default)
In buffered mode, status is returned when the last block of data has been
transferred to the tape drive’s buffer. See Chapter 24, “WRITE (0Ah)” for more
information about how data is buffered.
In unbuffered mode, status is returned only after the data has actually been
written to the tape.
OCTOBER 2008
VXA-2 TAPE DRIVE
9-3
CHAPTER 9 MODE SELECT (15h)
Byte 02, Bits 3 through 0 – Speed
The tape drive operates as a variable-speed device, where the tape drive
automatically determines the optimum speed required. The valid value for
this field is 0.
Byte 03 – Block Descriptor Length
This field specifies the length of the Block Descriptor in bytes, as follows:
00h
No Block Descriptor is included
08h
An 8-byte Block Descriptor is included
Note: The tape drive does not support multiple block descriptors.
9.3.2
BLOCK DESCRIPTOR
The optional Block Descriptor defines the data format and other format
characteristics to be used by the tape drive when it writes data.
Bit
Byte
7
6
5
4
2
1
0
Density Code
00
01
3
(MSB)
Number of Blocks
02
(LSB)
03
Reserved
04
05
(MSB)
Block Length
06
(LSB)
07
Byte 00 – Density Code
The Density Code specifies the format the tape drive will use to write data.
The format specified in this field becomes the default format used by the tape
drive under the following conditions:
The tape is capable of accepting the specified format.
The tape is formatted or contains a single partition written from the
beginning of the partition.
9-4
SCSI REFERENCE
1009566-001
9.3 MODE PARAMETER DATA
By default, the tape drive uses the VXA-2 format. If you choose to send a
Density Code to the tape drive, refer to Table 9-2 for the values you can use
and their results. Illegal density settings result in Check Condition status with
a sense key of Illegal Request (5h), the ASC is 30h and the ASCQ is 02h.
Table 9-2 Values for the Density Code field in the MODE SELECT command
Density Data format Notes
Code
Used
No change
in format
You can use this Density Code if you do not want to change the tape format. The
format will remain the same as it was before the MODE SELECT command was
sent to the tape drive. If the tape is not at LBOT, you must use either 7Fh or the
Density Code reported by the MODE SENSE command.
80h
VXA-1
format
The tape drive writes data using the VXA-1 format so that the tape can be read
by a VXA-1 tape drive.
Note: This format is not recommended for the V23 (230 meter) cartridges. These
cartridges are incompatible with the VXA-1 tape drive.
81h
VXA-2
format
The tape drive writes data using the VXA-2 format.
Note: VXA-1 tape drives cannot read tapes written in this format.
7Fh
Bytes 01 through 03 – Number of Blocks
The tape drive ignores this field in the MODE SELECT data.
Bytes 05 through 07 – Block Length
This field indicates the length of each logical block, in bytes, when the Fixed bit
is set for the READ, VERIFY, and WRITE commands. The default Block Length
is 3C000h (245,760 bytes= 240 KB). Valid values for this field are from 0h to
3C000h (see page 13-2 for additional information).
When the Block Length is non-zero, fixed-length block operations are
allowed. For fixed-length blocks, only block sizes that are evenly divisible by
four (that is, they end on a 4-byte boundary) are valid. A block length of 0 is
invalid for fixed-length blocks.
When the Block Length is 0, only variable-length block operations are
allowed.
Note: If the Block Length is 0, the SILI bit in the READ command suppresses
illegal length indications for both underlength and overlength reads. If the
Block Length is non-zero, the SILI bit of the READ command suppresses
illegal length indications only for blocks shorter than requested. See
page 12-2 for more information.
OCTOBER 2008
VXA-2 TAPE DRIVE
9-5
CHAPTER 9 MODE SELECT (15h)
9.4
READ-WRITE ERROR RECOVERY PAGE (PAGE CODE 01h)
The Read-Write Error Recovery page specifies error recovery parameters used
during read or write operations.
Bit
Byte
00
7
6
5
3
Reserved
2
1
0
DTE
DCR
Page Code
Page Length
01
02
4
Reserved
TB
RSVD
EER
PER
Read Retry Count
03
04
...
Reserved
07
Write Retry Count
08
09
...
Reserved
11
Byte 00, Bits 5 through 0 – Page Code
The value for this field is 01h, identifying the current page as the Read-Write
Error Recovery page.
Byte 01 – Page Length
This field indicates the number of bytes in the Read-Write Error Recovery page
that follow this byte. The valid value for this field is 0Ah (10 bytes).
Byte 02, Bit 5 – TB (Transfer Block)
The TB bit is not supported by the tape drive. The valid value for this bit is 0.
Byte 02, Bit 3 – EER (Enable Early Recovery)
The EER bit is not supported by the tape drive. The valid value for this bit is 0.
Byte 02, Bit 2 – PER (Post Error)
The PER bit is not supported by the tape drive. The valid value for this bit is 0.
Byte 02, Bit 1 – DTE (Disable Transfer on Error)
The DTE bit is not supported by the tape drive. The valid value for this bit is 0.
Byte 02, Bit 0 – DCR (Disable Correction)
The DCR bit is not supported by the tape drive. The valid value for this bit is 0.
9-6
SCSI REFERENCE
1009566-001
9.5 DISCONNECT-RECONNECT PAGE (PAGE CODE 02h)
Byte 03 – Read Retry Count
This field specifies how many times the tape drive attempts its read recovery
algorithms. If the tape drive fails to reread the block after this number of
attempts, it reports an unrecoverable error. You can set the Read Retry Count
to any value between 00h and FFh. The default is 05h. Any value greater than
05h is automatically set to 05h.
The value you specify for the Read Retry Count determines what operation
the tape drive performs when it encounters an unreadable data block, as
follows:
If you specify 00h for this byte, the tape drive does not attempt any rereads
before reporting an unrecoverable read error and continuing with the read
operation.
If you specify 01h to 05h for this byte, the tape drive attempts its read
recovery algorithm for either the default number of times or the number
specified by this byte, whichever is smaller, before reporting an
unrecoverable read error and continuing with the read operation.
Byte 08 – Write Retry Count
This field specifies how many times the tape drive should rewrite a physical
block before a recovery is attempted. You can set the Write Retry Count to any
value between 00h and FFh. The default value is 05h. Any value greater than
05h is automatically set to 05h.
To prevent the tape drive from rewriting any physical blocks, set the Write
Retry Count to 0 (00h). When the Write Retry Count is set to 0, the tape drive
will abort the write operation the first time it encounters a write error. The tape
drive returns Check Condition status with a sense key of Medium Error (3h),
with an ASC of 0Ch and ASCQ of 00h (Write Error).
9.5
DISCONNECT-RECONNECT PAGE (PAGE CODE 02h)
The Disconnect-Reconnect page specifies parameters that control how the
tape drive disconnects and reconnects during data transfers.
Bit
Byte
7
6
5
4
3
Reserved
00
Page Length
02
Buffer Full Ratio
03
Buffer Empty Ratio
(MSB)
05
OCTOBER 2008
1
0
Page Code
01
04
2
Bus Inactivity Limit
(LSB)
VXA-2 TAPE DRIVE
9-7
CHAPTER 9 MODE SELECT (15h)
Bit
Byte
06
7
6
(MSB)
(MSB)
3
2
1
0
(LSB)
Connect Time Limit
09
10
4
Disconnect Time Limit
07
08
5
(MSB)
(LSB)
Maximum Burst Size
11
Reserved
12
(LSB)
DTDC
13
Reserved
14
15
Byte 00, Bits 5 through 0 – Page Code
The value for this field is 02h, identifying the current page as the
Disconnect-Reconnect page.
Byte 01 – Page Length
This field indicates the number of bytes in the Disconnect-Reconnect page that
follow this byte. The valid value for this field is 0Eh (14 bytes).
Byte 02 – Buffer Full Ratio
The tape drive does not support this field. The valid value for this field is 0.
The tape drive manages the data buffer by adjusting the tape speed and by
pausing and resuming tape motion as necessary to match the initiator’s data
transfer rate.
Byte 03 – Buffer Empty Ratio
The tape drive does not support this field. The valid value for this field is 0.
The tape drive manages the data buffer by adjusting the tape speed and by
pausing and resuming tape motion as necessary to match the initiator’s data
transfer rate.
Bytes 04 and 05 – Bus Inactivity Limit
The tape drive does not support this field. The valid value for this field is 0.
Bytes 06 and 07 – Disconnect Time Limit
The tape drive does not support this field. The valid value for this field is 0.
Bytes 08 and 09 – Connect Time Limit
The tape drive does not support this field. The valid value for this field is 0.
9-8
SCSI REFERENCE
1009566-001
9.6 CONTROL MODE PAGE (PAGE CODE 0Ah)
Bytes 10 and 11 – Maximum Burst Size
This field specifies the amount of data, in 512-byte increments, that can be
transferred between the initiator and the tape drive before a disconnect is
required. The tape drive supports all values for this field. The default is 0,
which means that there is no limit to the amount of data that can be
transferred before a disconnect is required.
Byte 12, Bits 1 and 0 – DTDC (Data Transfer Disconnect Control)
This field specifies how the tape drive should perform a disconnect. Table 9-3
lists the valid values for this field.
Table 9-3 Valid values for the MODE SELECT DTDC field
DTDC
Value
9.6
Description
00b
Disconnects are not controlled by the DTDC field. Disconnects are
controlled by the other fields on this page. (Power-on default)
01b
Once the data transfer of a command has started, the tape drive
should not disconnect until all of the data has been transferred. The
Maximum Burst Size (bytes 10 and 11) must be set to 0.
10b
Not valid.
11b
Once the data transfer of a command has started, the tape drive
should not disconnect until the command is complete. The
Maximum Burst Size (bytes 10 and 11) must be set to 0.
CONTROL MODE PAGE (PAGE CODE 0Ah)
The Control Mode page specifies whether the tape drive returns Check
Condition status when one of its write and read error counters reaches a
specified threshold. For information about using the LOG SELECT command
to set threshold values for the tape drive’s write and read error counters, refer
to Chapter 7.
Bit
Byte
7
6
5
4
RSVD
00
1
0
Page Length
RSVD
02
Queue Algorithm Modifier
03
EECA
RLEC
Reserved
Reserved
RAENP
QErr
DQue
UAAENP
EAENP
Reserved
05
06
2
Page Code
01
04
3
(MSB)
07
OCTOBER 2008
Ready AEN Holdoff Period
(LSB)
VXA-2 TAPE DRIVE
9-9
CHAPTER 9 MODE SELECT (15h)
Byte 00, Bits 5 through 0 – Page Code
The value for this field is 0Ah, identifying the current page as the Control
Mode page.
Byte 01 – Page Length
This field indicates the number of bytes in the Control Mode Page that follow
this byte. The valid value for this field is 06h (6 bytes).
Byte 02, Bit 0 – RLEC (Report Log Exception Condition)
This field indicates whether the tape drive returns Check Condition status
with the sense key set to Unit Attention (6h) when one of its write or read error
counters reaches a specified threshold, as follows:
0
Do not return Unit Attention when a threshold condition
is met
1
Return Unit Attention when a threshold condition is met
Byte 03, Bits 7 through 4 – Queue Algorithm Modifier
The tape drive does not support the Simple Queue Tag message. The valid
value for this field is 0.
Byte 03, Bit 1 – QErr (Queue Error)
The tape drive does not support the Simple Queue Tag message. The valid
value for this field is 0.
Byte 03, Bit 0 – DQue (Disable Queuing)
The tape drive does not support the Simple Queue Tag message. The valid
value for this field is 1.
Byte 04, Bit 7 – EECA (Enable Extended Contingent Allegiance)
The tape drive does not support extended contingent allegiance. The valid
value for this bit is 0.
Byte 04, Bit 2 – RAENP (Ready AEN Permission)
The tape drive does not support asynchronous event notification (AEN). The
valid value for this bit is 0.
Byte 04, Bit 1 – UAAENP (Unit Attention AEN Permission)
The tape drive does not support asynchronous event notification. The valid
value for this bit is 0.
Byte 04, Bit 0 – EAENP (Enable AEN Permission)
The tape drive does not support asynchronous event notification. The valid
value for this bit is 0.
9-10
SCSI REFERENCE
1009566-001
9.7 DATA COMPRESSION PAGE (PAGE CODE 0Fh)
Bytes 06 and 07 – Ready AEN Holdoff Period
The tape drive does not support asynchronous event notification. The valid
value for this field is 0.
9.7
DATA COMPRESSION PAGE (PAGE CODE 0Fh)
The Data Compression page enables you to turn data compression on or off at
any position on the tape. To turn compression off, send this page with the DCE
bit set to 0. To turn compression back on, send this page with the DCE bit set
to 1.
Bit
Byte
7
6
5
4
RSVD
00
2
1
Page Length
02
DCE
03
DDE
DCC
Reserved
RED
Reserved
(MSB)
…
Compression Algorithm
(LSB)
07
08
0
Page Code
01
04
3
(MSB)
…
Decompression Algorithm
(LSB)
11
12
…
Reserved
15
Byte 00, Bits 5 through 0 – Page Code
The value for this field is 0Fh, identifying the current page as the Data
Compression page.
Byte 01 – Page Length
This field indicates the number of bytes in the Data Compression page that
follow this byte. The valid value for this field is 0Eh (14 bytes).
Byte 02, Bit 7 – DCE (Data Compression Enable)
This field enables or disables data compression, as follows:
OCTOBER 2008
0
Data compression is disabled
1
Data compression is enabled (default setting)
VXA-2 TAPE DRIVE
9-11
CHAPTER 9 MODE SELECT (15h)
The setting of the DCE bit remains in effect across all operations (rewinds,
loads, and so forth) until you change it. You can change the default setting
using the DfNoCmp (Default No Compression) bit on the Vendor Unique
Parameters Page 1 mode page (see page 9-26).
Byte 02, Bit 6 – DCC (Data Compression Capable)
The tape drive ignores this bit in the MODE SELECT command.
Byte 03, Bit 7 – DDE (Data Decompression Enable)
This field indicates whether data decompression is enabled. The tape drive
automatically decompresses compressed data before sending it to the initiator.
The tape drive ignores this bit.
Byte 03, Bits 6 and 5 – RED (Report Exception on Decompression)
The tape drive does not report exceptions on decompression (boundaries
between compressed and uncompressed data). The valid value for this field
is 0.
Bytes 04 through 07 – Compression Algorithm
The tape drive ignores this field in the MODE SELECT command.
Bytes 08 through 11 – Decompression Algorithm
The tape drive ignores this field in the MODE SELECT command.
9-12
SCSI REFERENCE
1009566-001
9.8 DEVICE CONFIGURATION PAGE (PAGE CODE 10h)
9.8
DEVICE CONFIGURATION PAGE (PAGE CODE 10h)
Bit
Byte
7
6
5
4
3
Reserved
00
2
Page Length
RSVD
02
CAP
CAF
Active Format
03
Active Partition
04
Write Buffer Full Ratio
05
Read Buffer Empty Ratio
(MSB)
Write Delay Time
07
DBR
08
BIS
RSmk
AVC
(LSB)
SOCF
RBO
REW
Gap Size
09
EOD Defined
10
11
0
Page Code
01
06
1
EEG
SEW
Reserved
(MSB)
Buffer Size at Early Warning
12
(LSB)
13
14
Select Data Compression Algorithm
15
Reserved
Byte 00, Bits 5 through 0 – Page Code
The value for this field is 10h, identifying the current page as the Device
Configuration page.
Byte 01 – Page Length
This field indicates the number of bytes in the Device Configuration page that
follow this byte. The valid value for this field is 0Eh.
Byte 02, Bit 6 – CAP (Change Active Partition)
If the loaded tape is partitioned, this bit indicates that you want to move the
tape from the current partition to a new partition specified by the Active
Partition byte (byte 03), as follows:
OCTOBER 2008
0
Do not change the active partition
1
Change the active partition to the partition specified by the
Active Partition byte
Changing partitions may cause tape motion.
VXA-2 TAPE DRIVE
9-13
CHAPTER 9 MODE SELECT (15h)
If this bit is set to 1, the tape drive positions the tape to the logical beginning of
the new partition (LBOP) after receiving a tape motion command. If the
partition specified by the Active Partition field is the same as the currently
active partition, the tape drive rewinds to the beginning of the current
partition.
Note: If the currently loaded tape does not contain partitions, the value for this
bit must be 0.
Byte 02, Bit 5 – CAF (Change Active Format)
The tape drive ignores this field.
Byte 02, Bits 4 through 0 – Active Format
The Active Format function is not implemented. The tape drive ignores this
field.
Byte 03 – Active Partition
This field indicates the number of the new partition to which the tape is to be
moved (if you set the CAP bit to 1 to change the active partition). The tape
positioned to the logical beginning of partition (LBOP) for the specified
partition. The valid values for this field are 0 and 1.
Notes:
If the tape is not partitioned, the value in the Active Partition field must be 0.
If the CAP bit is 0, the tape drive ignores the Active Partition byte.
If you specify a partition that does not exist, the tape drive returns Check
Condition status with the sense key set to Illegal Request.
Byte 04 – Write Buffer Full Ratio
The tape drive does not support this field. The valid value for this field is 0.
The tape drive manages the data buffer by adjusting the tape speed and by
pausing and resuming tape motion as necessary to match the initiator’s data
transfer rate.
Byte 05 – Read Buffer Empty Ratio
The tape drive does not support this field. The valid value for this field is 0.
The tape drive manages the data buffer by adjusting the tape speed and by
pausing and resuming tape motion as necessary to match the initiator’s data
transfer rate.
Bytes 06 and 07 – Write Delay Time
The value specified by this field determines the maximum amount of time, in
units of 100 msec, that the data will remain in the buffer in the absence of an
event that would normally empty the buffer. When the time specified by Write
Delay Time elapses, the data in the buffer is written to tape.
9-14
SCSI REFERENCE
1009566-001
9.8 DEVICE CONFIGURATION PAGE (PAGE CODE 10h)
Valid values for this field are 0000h to FFFFh. The default value for this field is
0000h. Any value greater than 1999h (approximately 11 minutes) is
automatically set to 1999h. At the end of the time specified by this field, the
data in the buffer is written to tape, followed by an EOD mark; drum rotation
is stopped.
Note: The longest time that data remains in the buffer before being written to
tape is 10 minutes.
Byte 08, Bit 7 – DBR (Data Buffer Recovery)
The tape drive does not support data buffer recovery. The valid value for this
bit is 0.
Byte 08, Bit 6 – BIS (Block Identifier Supported)
The tape drive ignores this field in the MODE SELECT command.
Byte 08, Bit 5 – RSmk (Report Setmarks)
This field specifies whether the tape drive returns Check Condition status
when it encounters a setmark on the tape during read, verify, space block, or
space filemark operations, as follows:
0
Do not report setmarks (setmarks are ignored)
1
Report setmarks (default setting)
If the RSmk bit is 1 and the tape drive encounters a setmark, it returns Check
Condition status with the sense key set to No Sense (0h). The ASC and ASQ
fields are set to 00h and 03h, respectively.
Byte 08, Bit 4 – AVC (Automatic Velocity Control)
The tape drive always uses automatic velocity control and ignores this bit.
Byte 08, Bits 3 and 2 – SOCF (Stop on Consecutive Filemarks)
The tape drive does not support the SOCF field. The valid value for this bit
is 0.
Byte 08, Bit 1 – RBO (Recover Buffer Order)
The tape drive does not support the RBO bit. The valid value for this bit is 0.
OCTOBER 2008
VXA-2 TAPE DRIVE
9-15
CHAPTER 9 MODE SELECT (15h)
Byte 08, Bit 0 – REW (Report Early Warning)
This field indicates whether reporting of the early-warning condition
(approaching LEOP) during a read operation is enabled or disabled, as
follows:
0
Do not report early-warning condition for read operations;
only report early warning condition for write operations
(default setting).
1
Report early-warning condition after completing the
current READ or WRITE command.
The tape drive reports an early-warning condition as a Check Condition status
with the sense key set to No Sense. The EOM bit is set to 1 and the LBOT bit is
set to 0 in the extended sense data.
Byte 09 – Gap Size
The tape drive does not support the Gap Size field. The valid value for this
field is 0.
Byte 10, Bits 7 through 5 – EOD Defined
The tape drive does not support the EOD field. The valid value for this field
is 0.
Byte 10, Bit 4 – EEG (Enable EOD Generation)
The tape drive ignores this bit in the MODE SELECT command.
Byte 10, Bit 3 – SEW (Synchronize at Early Warning)
The tape drive ignores this bit in the MODE SELECT command.
Bytes 11 through 13 – Buffer Size at Early Warning
The tape drive does not support the Buffer Size at Early Warning field. The
valid value for this field is 0.
Byte 14 – Select Data Compression Algorithm
The tape drive does not support the Select Data Compression Algorithm field.
The valid value for this field is 0.
9.9
MEDIUM PARTITION PAGE (PAGE CODE 11h)
The Medium Partition page allows you to format a tape to contain one or two
partitions. Partitions are numbered consecutively from the end of the tape
with partition 0 always being the last partition on the tape.
9-16
SCSI REFERENCE
1009566-001
9.9 MEDIUM PARTITION PAGE (PAGE CODE 11h)
Before formatting new partitions, you must position the tape at LBOT or at the
logical beginning of an existing partition.
Bit
Byte
7
6
5
4
3
Reserved
00
Page Length
02
Maximum Additional Partitions
03
Additional Partitions Defined
FDP
SDP
IDP
PSUM
05
Medium Format Recognition
06
Reserved
07
Reserved
08
(MSB)
09
10
(MSB)
11
1
0
Page Code
01
04
2
Reserved
Partition Size (Partition 0)
(LSB)
Partition Size (Partition 1)
(LSB)
12
...
Partition Size (Partitions 2 through 63)
135
Byte 00, Bits 5 through 0 – Page Code
The value for this field is 11h, identifying the current page as the Medium
Partition page.
OCTOBER 2008
VXA-2 TAPE DRIVE
9-17
CHAPTER 9 MODE SELECT (15h)
Byte 01 – Page Length
This field indicates the number of bytes in the Medium Partition page that
follow this byte.
06h
Only a single partition is allowed
08h
If two partitions are specified, the Partition 0 Size field
(bytes 08 and 09) is redefined as Partition 1 Size. This field
is then used to specify the size of partition 1. Partition 0 is
the remainder of the tape after partition 1 is created.
0Ah
If two partitions are specified, their sizes are set using the
Partition Size fields (bytes 8 and 9 for partition 0, bytes 10
and 11 for partition 1) and the FDP, SDP, and IDP fields.
86h
If two partitions are specified, their sizes are set using the
Partition Size fields (bytes 8 and 9 for partition 0, bytes 10
and 11 for partition 1) and the FDP, SDP, and IDP fields.
The tape drive ignores the remaining Partition Size fields
(bytes 12 through 135).
Byte 02 – Maximum Additional Partitions
The tape drive ignores this field in the MODE SELECT command.
Byte 03 – Additional Partitions Defined
This field indicates the number of partitions being defined in addition to the
original partition (the entire tape). Up to two partitions are allowed. Valid
values are either 00h or 01h.
If this byte is set to 00h, the tape drive ignores the sizes for partitions 0
through 63 in the Partition Size fields (bytes 08 through 135). The entire tape
is a single partition.
If this byte is set to 01, the tape drive ignores the sizes for partitions 2
through 63 in the Partition Size fields (bytes 12 through 135). The tape is
divided into two partitions.
Byte 04, Bit 7 – FDP (Fixed Data Partitions)
This field specifies whether the tape drive should use its “fixed” definition of
partitions to format the tape. The fixed definition is a single partition
encompassing the entire tape.
9-18
SCSI REFERENCE
0
Do not format the tape using fixed format
1
Format the tape with one partition
The Additional Partitions Defined, SDP, and IDP fields
must be set to 0. The Partition Size fields are ignored.
1009566-001
9.9 MEDIUM PARTITION PAGE (PAGE CODE 11h)
Byte 04, Bit 6 – SDP (Select Data Partitions)
This field specifies whether the tape drive should format the tape using the
number of partitions specified in the Additional Partitions Defined field, with
the size of the partitions determined by the tape drive. If no additional
partitions are specified, the tape will have a single partition encompassing the
entire capacity of the tape.
0
Do not format the tape using drive defined partitions
1
Format the tape with n+1 partitions, where n is the
number of partitions specified by the Additional Partitions
Defined field
The tape drive ignores the partition sizes specified in the
Partition Size fields. The size of partition 1 is automatically
set to 100 MB. Partition 0 will encompass the remaining
capacity of the tape.
Byte 04, Bit 5 – IDP (Initiator Defined Partitions)
This field specifies whether the tape drive should format the tape based on the
partition sizes provided by the initiator in the Partition Size fields, as follows:
0
Do not format the tape using initiator defined partitions
1
Format the tape with n+1 partitions, where n is the
number of partitions specified by the Additional Partitions
Defined field
The size of partition 1 is specified in the Partition 1 Size
field (bytes 10 and 11). Partition 0 will encompass the
remaining capacity of the tape and is at least 100 MB in
size.
Table 9-4 summarizes the results of all possible combinations of the FDP, SDP,
and IDP bits.
OCTOBER 2008
VXA-2 TAPE DRIVE
9-19
CHAPTER 9 MODE SELECT (15h)
Note: The FDP, SDP, and IDP bits are mutually exclusive. When one of these bits
is set to 1, the others must be 0.
Table 9-4 Partition characteristics resulting from the combinations of the FDP, SDP, and IDP bits in the
Medium Partition page
For these
combinations...
FDP SDP IDP
0
0
0
0
These results occur...
When Additional Partitions
Defined = 00h...
0
When Additional Partitions
Defined = 01h...
The tape drive does not format the tape.
The tape drive formats the
tape with one partition (the
entire tape).
The tape drive formats the tape with n+1 partitions,
where n is the number of partitions specified by the
Additional Partitions Defined field. The size of
partition 1 is specified in the Partition 1 Size field (bytes
10 and 11). Partition 0 is the remainder of the tape.
Note: If the Page Length field is set to 08h, the Partition
Size field for partition 1 moves to bytes 8 and 9. The
size for partition 0 is not specified, but encompasses
the remaining capacity of the tape.
The tape drive formats the
tape with one partition (the
entire tape).
The tape drive formats a tape with n+1 partitions,
where n is the number of partitions specified by the
Additional Partitions Defined field. The size of
Partition 1is set to 100 MB. Partition 0 is the remainder
of the tape.
1
0
1
0
0
1
1
Not valid.
1
0
0
The tape drive formats the tape with one partition (the entire tape).
1
0
1
1
1
0
1
1
1
Not valid.
Byte 04, Bits 4 and 3 – PSUM (Partition Size Unit of Measure)
This field indicates the units used to specify partition sizes. If you set IDP
(Initiator Defined Partitions) to 1 and are defining additional partitions
(Additional Partitions Defined = 1), use the PSUM field to indicate the units
you are using to specify the sizes of the additional partitions. The valid values
for PSUM are:
9-20
SCSI REFERENCE
00b
The partition size is specified in bytes
01b
The partition size is specified in kilobytes (KB)
10b
The partition size is specified in megabytes (MB)
1009566-001
9.9 MEDIUM PARTITION PAGE (PAGE CODE 11h)
Notes:
The minimum partition size on a partitioned tape is 100 MB. If you set
PSUM=00b (partition size in bytes) or PSUM=01b (partition size in
kilobytes), the tape drive rounds the specified partition sizes up to the
nearest 100 MB (102,400 KB). If you set PSUM=10b (partition size in
megabytes) and specify a partition size that is less that 100 MB, the tape
drive sets the partition size to 100 MB.
If you do not define any additional partitions (Additional Partitions
Defined = 0), the tape drive ignores the PSUM field.
If you do not use the Partition Size field to specify the partition size (that is,
FDP=1 or SDP=1), the tape drive ignores the PSUM field.
Byte 05 – Medium Format Recognition
The tape drive ignores this field in the MODE SELECT command.
Bytes 08 and 09 – Partition 0 Size
This field specifies the size of partition 0. Since the maximum number of
partitions is two, the tape drive ignores this field when creating a partitioned
tape (unless the Page Length field is set to 08h, in which case, this field
specifies the size of partition 1). Partition 0 will encompass the remaining
capacity of the tape after partition 1 is created. The minimum size of partition 0
on a partitioned tape is 100 MB.
Bytes 10 and 11 – Partition 1 Size
This field specifies the size of partition 1 when IDP=1. This size indicates the
approximate amount of uncompressed data that can be written between the
logical beginning of partition 1 (LBOP) and the logical end of partition 1
(LEOP) on the tape.
Use this field to specify the size of partition 1 using the units indicated in the
PSUM field (byte 04, bits 4 and 3). The minimum size of partition 1 on a
partitioned tape is 100 MB.
Bytes 12 through 135 – Partition Size (Partitions 2 through 63)
The tape drive does not support more than two partitions. The tape drive
ignores these fields.
OCTOBER 2008
VXA-2 TAPE DRIVE
9-21
CHAPTER 9 MODE SELECT (15h)
9.10 TAPEALERT PAGE (PAGE CODE 1Ch)
The TapeAlert page allows you to configure how the tape drive uses the
TapeAlert function.
Bit
Byte
00
7
6
5
4
Reserved
2
1
0
RSVD
LogErr
Page Code
Page Length
01
02
3
Perf
Reserved
DExcpt
Test
Reserved
03
MRIE
04
...
Interval Timer
07
08
...
Test Flag Number
11
Byte 00, Bits 5 through 0 – Page Code
The value for this field is 1Ch, which identifies the current page as the
TapeAlert page.
Byte 01 – Page Length
This field indicates the number of bytes in the TapeAlert page that follow this
byte. The valid value for this field is 0Ah.
Byte 02, Bit 7 – Perf (Performance)
This field specifies whether logging of informational exception operations that
can cause delays are acceptable, as follows:
0
Delays due to logging are not allowed (default setting)
1
Delays due to logging are allowed
Byte 02, Bit 3 – DExcpt (Disable Exception Reporting)
This field determines how the tape drive handles the reporting of
informational exception operations, as follows:
9-22
SCSI REFERENCE
0
The tape drive reports informational exceptions using the
method specified by the MRIE field.
1
The tape drive disables all informational exception
operations. The MRIE field is ignored (default setting).
1009566-001
9.10 TAPEALERT PAGE (PAGE CODE 1Ch)
Byte 02, Bit 2 – Test
This field determines whether the tape drive performs the TapeAlert test
specified in the Test Flag Number field, as follows:
0
The tape drive does not generate any false informational
exception conditions.
1
The tape drive generates a false informational exception
condition based on the Test Flag Number field (default
setting).
The next SCSI command after the MODE SELECT
command returns Check Condition status with sense key
set to Unit Attention (6h). The ASC and ASCQ fields are set
to 5Dh and 00h, respectively. If the Test Flag Number is set
to 0 and both the Test and DExcpt bits are set to 1, then
the MODE SELECT command will be rejected as an Illegal
Request.
Byte 02, Bit 0 – LogErr
This field indicates whether the tape drive logs informational exception
conditions. The tape drive ignores the LogErr bit.
Byte 03, Bits 3 through 0 – MRIE (Method of Reporting Exception
Information)
This field indicates the method used by the tape drive to report informational
exception conditions. Table 9-5 lists the valid values for MRIE.
Table 9-5 Valid values for MRIE in the MODE SELECT command
MRIE
OCTOBER 2008
Description
0h
Do not report informational exceptions.
2h
Generate a Check Condition status with the sense key set to Unit
Attention (6h).
3h
Generate a Check Condition status with the sense key set to Recovered
Error (01h), if the reporting of recovered errors is allowed. Since the tape
drive does not support the PER bit (see page 9-6), this setting has the
same effect as setting MRIE to 0h.
4h
Generate a Check Condition status with the sense key set to Recovered
Error (01h), regardless of the PER bit.
5h
Generate a Check Condition status with the sense key set to No Sense
(00h).
6h
Report informational exceptions only in response to an unsolicited
REQUEST SENSE command.
VXA-2 TAPE DRIVE
9-23
CHAPTER 9 MODE SELECT (15h)
Bytes 04 through 07 – Interval Timer
The tape drive does not support this field. The valid value for this field is 0.
Bytes 08 through 11 – Test Flag Number
The value in this field indicates what action the tape drive should take if the
Test bit is set to 1, as follows:
Table 9-6 Test Flag Number settings for MODE SELECT
Test Flag Number Description
0
Generate a false information exception condition.
1 through 64
–1 through –64
Set the TapeAlert Flag indicated by the number and process.
Clear the TapeAlert Flag indicated by the number.
Set all supported TapeAlert Flags. See Table 8-6 on
page 8-11 for a list of the supported TapeAlert Flags.
32767
9.11 VENDOR UNIQUE PARAMETERS PAGE 1 (PAGE CODE 21h)
The Vendor Unique Parameters page is used to set options for the tape drive
that are unique to Tandberg Data.
Bit
Byte
00
7
6
5
4
3
Reserved
2
1
0
QueLoad
NoNgRs
Page Code
Page Length
01
02
Reserved
03
04
Reserved
ChkClnRq
05
SOPR
DfNoCmp
Reserved
ExInq
RSVD
ServReq
FvCpcty
NoSvPtr
RespDuringImmed
Byte 00, Bits 5 through 0 – Page Code
The value for this field is 21h, identifying the current page as the Vendor
Unique Parameters Page 1 page.
Byte 01 – Page Length
This field specifies the number of bytes in the Vendor Unique Parameters
Page 1 page that follow this byte. The valid value for this field is 04h (4 bytes).
9-24
SCSI REFERENCE
1009566-001
9.11 VENDOR UNIQUE PARAMETERS PAGE 1 (PAGE CODE 21h)
Byte 04, Bit 6 – ChkClnRq (Check Condition on Cleaning Required)
This field indicates whether the device sends a Check Condition for a single
SCSI command after it is determined that a cleaning cartridge use is necessary.
0b
Do not send Check Condition for SCSI command when
cleaning cartridge use is required
1b
Send Check Condition for SCSI command when cleaning
cartridge use is required
This field is kept in non-volatile RAM, and once set, remains in effect even
between power-on cycles, until the value has been changed by this command.
Byte 04, Bit 2 – ServReq (Service Required)
This field indicates whether the device requires servicing before normal
operations may be resumed.
0b
Service is required, normal operations may not be allowed
1b
Service is not required, normal operations are allowed
This field is kept in non-volatile RAM, and once set, remains in effect, even
between power-on cycles, until the tape drive is serviced or the value has been
changed by this command.
Byte 04, Bit 1 – QueLoad (Queue Load Command During Load)
This field indicates whether the tape drive will queue a LOAD command
received while the tape drive is performing an automatic cartridge load.
0b
Report busy for LOAD command during autoload
1b
Queue LOAD command during autoload
The value for this field is stored in nonvolatile memory and remains in effect
through power cycles, until changed again by the MODE SELECT command.
Byte 04, Bit 0 – NoNgRs (No Negative Residuals)
This bit specifies whether the tape drive reports residual values on backward
space operations as positive or negative (2’s compliment) numbers, as follows:
0b
Report residuals as negative numbers (2’s compliment)
(default setting)
1b
Report residuals as positive numbers
The value for this field is stored in nonvolatile memory and remains in effect
through power cycles.
OCTOBER 2008
VXA-2 TAPE DRIVE
9-25
CHAPTER 9 MODE SELECT (15h)
Note: 2’s complement is the method of representing a negative number as a
binary number that when added to a positive number of the same
magnitude equals zero.
Byte 05, Bit 7 – SOPR (SCSI Operating Parameter Restoration)
This bit specifies whether the tape drive should restore SCSI operating
parameters (the settings for synchronous/asynchronous transfers,
narrow/wide transfers, transfer rate, and offset for synchronous transfers)
when it detects that its firmware has been updated.
0b
Do not restore SCSI operating parameters after a firmware
update (default setting
1b
Restore the SCSI operating parameters after a firmware
update
The value for this field is stored in nonvolatile memory and remains in effect
through power cycles.
Byte 05, Bit 6 – DfNoCmp (Default No Compression)
This bit specifies whether the tape drive should permanently default to having
write compression disabled at power up.
0b
Permanently default to compression enabled (default
setting)
1b
Permanently default to compression disabled
The value for this field is stored in nonvolatile memory and remains in effect
through power cycles.
Note: Regardless of the setting for this bit, compression can still be enabled or
disabled using the DCE bit (byte 2, bit 7 on the Data Compression page).
Byte 05, Bit 5 – ExInq (Extended Inquiry Overwrite)
This bit specifies whether the tape drive should permanently overwrite an
extended area of the Standard Inquiry data when the SEND DIAGNOSTIC Set
Inquiry Data page (86h) is sent to the tape drive, as follows:
9-26
SCSI REFERENCE
0b
Permanently overwrite only the Vendor Identification and
Product Identification fields (bytes 8 through 31) of the
Standard Inquiry Data (default setting)
1b
Permanently overwrite the Product Revision Level and
four bytes of Vendor Specific data (bytes 32 through 39) in
addition to the Vendor Identification and Product
Identification fields in the Standard Inquiry Data
1009566-001
9.11 VENDOR UNIQUE PARAMETERS PAGE 1 (PAGE CODE 21h)
The value for this field is stored in nonvolatile memory and remains in effect
through power cycles.
Byte 05, Bit 3 – FvCpcty (Favor Capacity)
This bit specifies whether the tape drive should favor tape capacity over write
speed when managing the data buffer during a write operation, as follows:
0b
Favor write speed over capacity (default setting)
1b
Favor capacity (the amount of data that can be written to
tape) over write speed
The value for this field is stored in nonvolatile memory and remains in effect
through power cycles.
Byte 05, Bit 2 – NoSvPtr (No Save Pointer on Read)
This bit specifies whether the tape drive should omit the Save Data Pointer
message when disconnecting from the SCSI bus during a read operation, as
follows:
0b
Send a Save Data Pointer message before sending a
Disconnect message during a read operation (default
setting)
1b
Omit the Save Data Pointer message before sending a
Disconnect message during a read operation
The value for this field is stored in nonvolatile memory and remains in effect
through power cycles.
Byte 05, Bits 0 and 1 – RespDuringImmed (Response During Immediate)
This field indicates how the tape drive responds to any motion command
when the command is received while the tape drive is busy completing
another immediate command (ERASE, LOAD, LOCATE, REWIND, WRITE
FILEMARK, and VERIFY). Table 9-7 lists the valid values for this field.
Table 9-7 Valid values for RespDuringImmed in the MODE SELECT command
RespDuringImmed Description
Value
OCTOBER 2008
00b
Return Busy status. (default setting)
01b
Return Check Condition status. The sense key is set to 2h
(Not Ready) with the ASC and ASCQ set to 04h and 01h,
respectively.
VXA-2 TAPE DRIVE
9-27
CHAPTER 9 MODE SELECT (15h)
Table 9-7 Valid values for RespDuringImmed in the MODE SELECT command
RespDuringImmed Description
Value
10b
Queue the command until the immediate command is
complete. If a second command is received, return Busy
status.
11b
Reserved
9.12 EXCEPTIONS AND ERROR CONDITIONS
Table 9-8 lists the exceptions and error conditions that cause the tape drive to
return Check Condition status for the MODE SELECT command.
Note: If the Medium Partition page is sent, causing the current tape to be
formatted, motion and write errors may occur. See the WRITE command
(Chapter 24) for error conditions that may arise in this situations.
Table 9-8 REQUEST SENSE data for MODE SELECT command errors and exceptions
Sense
ASC
ASCQ Description
Key (Byte 12) (Byte 13)
5h
1Ah
00h
Illegal Request. Parameter List Length Error. The Parameter List Length
was too small and caused the Parameter List Header, the Block Descriptor,
or a parameter page to be truncated.
5h
24h
00h
Illegal Request. Invalid field in the CDB.The SP bit in the CDB is set to 1.
5h
25h
00h
Illegal Request. Logical unit not supported.
5h
26h
00h
Illegal Request. Parameter List Length Error. The Page Length does not
match the actual length of the specified page.
02h
Illegal Request. Invalid value in parameter list. This error is a result of any
of the following:
ƒ The Buffered Mode field in the Parameter List Header is not set to either
000b (unbuffered) or 001b (buffered).
ƒ The Block Descriptor Length field in the Parameter List Header is not set
to either 00h (no descriptor) or 08h (the size of the Block Descriptor).
ƒ The Density Code field in the Block Descriptor is set to a value other
than 7Fh (no change), 80h (VXA-1 format), or 81h (VXA-2 format).
ƒ The Block Length field in the Block Descriptor is set to a value greater
than 3C00h (240 bytes).
ƒ The Block Length field in the Block Descriptor is set to a non-zero value
(fixed-length blocks) and the specified value is not evenly divisible by 4.
ƒ The Page Length field for the specified page does not match the actual
length of the field.
ƒ The TB, EER, PER, DTE, or DCR bit in the Read-Write Recovery page are
set to 1.
5h
9-28
26h
SCSI REFERENCE
1009566-001
9.12 EXCEPTIONS AND ERROR CONDITIONS
Table 9-8 REQUEST SENSE data for MODE SELECT command errors and exceptions (continued)
Sense
ASC
ASCQ Description
Key (Byte 12) (Byte 13)
5h
26h
02h
Illegal Request. Invalid value in parameter list. (continued)
ƒ The Buffer Full Ratio, Buffer Empty Ratio, Bus Inactivity Limit, Disconnect
Time Limit, or Connect Time Limit field in the Disconnect-Reconnect
page is not set to 0.
ƒ The QErr, EECA, RAENP, UAAENP, or EAENP bit in the Control Mode
page is set to 1.
ƒ The DQue field in the Control Mode page is set to 0.
ƒ The Queue Algorithm Modifier or Ready AEN Holdoff Period field in the
Control Mode page is not set to 0.
ƒ The RED field in the Data Compression page is set to 1.
ƒ The Compression Algorithm or Decompression Algorithm field in the
Data Compression page is not set to 0.
ƒ The CAF, DBR, RBO field in the Device Configuration page is set to 1.
ƒ The Active Format, Write Buffer Full Ratio, Read Buffer Full, SOCF, Gap
Size, EOD, Buffer Size at Early Warning, or Select Data Compression
Algorithm field in the Device Configuration page is not set to 0.
ƒ The Additional Partitions Defined field is set to a value greater than 3Fh
(63 partitions).
ƒ More than one of the FDP, SDP, and IDP bits in the Medium Partition
page are set to 1.
ƒ The PSUM field in the Medium Partition page is set to 11b.
ƒ The IDP field on the Medium Partition page is set to 1 and the sum of
the Partition Size 0 and Partition Size 1 fields is greater than the size of
the tape.
6h
2Ah
01h
Unit Attention. MODE SELECT parameters have been changed.The tape
drive sends status to all other initiators on the SCSI bus.
Bh
47h
00h
Aborted Command. SCSI parity error. The command was aborted
because of a SCSI bus parity error.
OCTOBER 2008
VXA-2 TAPE DRIVE
9-29
CHAPTER 9 MODE SELECT (15h)
Notes
9-30
SCSI REFERENCE
1009566-001
10
MODE SENSE (1Ah)
Bit
Byte
7
6
5
4
3
2
1
0
00
0
0
0
1
1
0
1
0
RSVD
DBD
01
02
Logical Unit Number
PC
Reserved
Page Code
03
Reserved
04
Allocation Length
05
Control
10.1 ABOUT THIS COMMAND
The MODE SENSE command allows the tape drive to report medium and
device parameters to the initiator. These parameters apply to all initiators in a
multi-initiator environment. The parameters are transferred to the initiator as
a parameter list comprised of the following:
Parameter List Header
Block Descriptor (optional)
One or more pages of related mode parameters
The values returned in response to this command reflect values set by
previous MODE SELECT commands or the default values (if the tape drive
has been power-cycled or reset by either a SCSI bus reset or a Bus Device
Reset).
10.2 CDB FIELD DEFINITIONS
Logical Unit Number (LUN) – Byte 01, Bits 7 through 5
The tape drive only supports LUN 0. The value for this field must be 0.
OCTOBER 2008
VXA-2 TAPE DRIVE
10-1
CHAPTER 10 MODE SENSE (1Ah)
Byte 01, Bit 3 – DBD (Disable Block Descriptor)
This field indicates whether the tape drive returns the Block Descriptor as part
of the MODE SENSE parameter data, as follows:
0
Send the Block Descriptor
1
Do not send the Block Descriptor
Byte 02, Bits 7 and 6 – PC (Page Control)
This field specifies the type of mode parameter values to be returned in the
MODE SENSE data. Table 10-1 lists the valid values for this field.
Table 10-1 Valid values for the PC field in the MODE SENSE command
PC Setting Description
00b
Return the values set by the last successful MODE SELECT command
or if a MODE SELECT command has not been executed since the last
tape drive reset, return the power-on default values.
01b
Return all values that are changeable. The changeable values are
indicated by a 1 in each bit of each changeable field.
10b
Return the default values. (Values set in the EEPROM.)
11b
Return saved parameters. Not supported.
Byte 02, Bits 5 through 0 – Page Code
This field specifies which MODE SENSE parameter page or pages the initiator
is requesting. Table 10-2 lists the valid values for this field.
Table 10-2 Valid values for the Page Code field in the MODE SENSE
command
Specify this
Page Code...
10-2
SCSI REFERENCE
To return this Mode page...
With this
Page Length
01h
Read-Write Error Recovery Page
0Ch (12 bytes)
02h
Disconnect/Reconnect Page
10h (16 bytes)
0Ah
Control Mode Page
08h (8 bytes)
0Fh
Data Compression Page
10h (16 bytes)
10h
Device Configuration Page
10h (16 bytes)
11h
Medium Partition Page
88h (136 bytes)
1Ch
TapeAlert Page
0Ch (12 bytes)
21h
Vendor Unique Parameters Page 1
06h (6 bytes)
22h
Vendor Unique Parameters Page 2
0Ah (10 bytes)
3Fh
All available pages (in ascending page code order) F4h (244 bytes)
1009566-001
10.3 WHAT THE TAPE DRIVE RETURNS
Byte 04 – Allocation Length
The Allocation Length indicates the amount of memory in bytes that the
initiator has allocated for the return of MODE SENSE parameters. To
determine the Allocation Length, total the number of bytes in the Parameter
List Header (4 bytes), Block Descriptor (8 bytes, if you are requesting it), and all
parameter pages you are requesting. Or, to receive all available data, specify
F4h (244 bytes). Table 10-2 lists the page lengths of all the supported mode
pages.
If the Allocation Length is smaller than the amount of data available from the
tape drive, the returned data is truncated. If the Allocation Length is greater
than the amount of data to be returned, only the number of bytes available are
transferred; no additional data is transferred.
10.3 WHAT THE TAPE DRIVE RETURNS
This section describes the log page format and the log pages that the tape
drive supports. The MODE SENSE command returns the single log page
specified in the Page Code field of the CDB.
Each log page begins with a four-byte Parameter List Header (bytes 00 through
03), followed by zero or more variable-length log parameters defined for that
page. The Parameter List Header specifies the page code for the log parameter
data being returned and indicates the total length of the data to follow.
Bit
Byte
7
6
5
4
3
00
Mode Data Length
01
Medium Type
02
03
WP
Buffered Mode
2
1
0
Speed
Block Descriptor Length
Byte 00 – Mode Data Length
This field indicates the number of bytes of MODE SENSE data that are
available for transfer, excluding this field. The value returned for this field is
the remaining number of bytes in the Parameter List Header plus the number of
bytes of data to be returned based on the field settings in the CDB.
Note: The value returned for the Mode Data Length does not reflect the value
you specified for the Allocation Length in the CDB.
OCTOBER 2008
VXA-2 TAPE DRIVE
10-3
CHAPTER 10 MODE SENSE (1Ah)
Byte 01 – Medium Type
This field indicates the type of media in the data cartridge currently loaded in
the tape drive. Table 10-3 shows the valid values for this field.
Table 10-3 Values returned for Medium Type field in MODE SENSE data
Value
returned
Length of tape loaded
00h
No cartridge loaded, cleaning cartridge loaded, or tape is
unknown, broken, or unreadable
81h
VXA-1 standard media
82h
VXA-2 standard media
Byte 02, Bit 7 – WP (Write Protect)
This field indicates whether the data cartridge loaded in the tape drive is write
protected, as follows:
0
The data cartridge is not write protected
1
The data cartridge is write protected
Byte 02, Bits 6 through 4 – Buffered Mode
This field indicates the data transfer mode to be used by the tape drive during
a write operation, as follows:
000b
Unbuffered mode
001b
Buffered mode (Power-on default)
In buffered mode, status is returned when the last block of data has been
transferred to the tape drive’s buffer. See Chapter 24, “WRITE (0Ah)“ for a
detailed description of how data is buffered.
In unbuffered mode, status is returned only after the data has actually been
written to the tape.
Byte 02, Bits 3 through 0 – Speed
The value returned for this field is 0, indicating that the tape drive operates as
a variable-speed device and automatically determines the optimum speed
required.
10-4
SCSI REFERENCE
1009566-001
10.3 WHAT THE TAPE DRIVE RETURNS
Byte 03 – Block Descriptor Length
This byte indicates the length of the Block Descriptor in bytes, as follows:
00h
No Block Descriptor is included
08h
An 8-byte Block Descriptor is included
Note: The tape drive does not support multiple block descriptors.
10.3.1
Bit
Byte
7
6
BLOCK DESCRIPTOR
5
4
2
1
(MSB)
Number of Blocks
02
(LSB)
03
Reserved
04
05
0
Density Code
00
01
3
(MSB)
Block Length
06
(LSB)
07
Byte 00 – Density Code
This field indicates the format of the data cartridge currently in the tape drive.
If a data cartridge is not loaded or the tape is not formatted, this field indicates
the preferred format for the tape. The tape drive will use the preferred format
if it is compatible with the currently loaded cartridge and the tape is formatted
or if the tape contains a single partition written from the beginning of the
partition. Table 10-4 lists the values returned for this field.
Table 10-4 Values for the Density Code field in the MODE SENSE command
Density Data format Notes
Code
Used
80h
VXA-1
format
The tape drive detected a VXA-1 formatted tape or will use VXA-1 format when
formatting or writing to the tape.
81h
VXA-2
format
The tape drive detected a VXA-2 formatted tape or will use VXA-2 format when
formatting or writing to the tape.
Bytes 01 through 03 – Number of Blocks
This field indicates the total capacity of the tape, between LBOT and LEOT, in
approximately 16-KB physical units (the default block size).
OCTOBER 2008
VXA-2 TAPE DRIVE
10-5
CHAPTER 10 MODE SENSE (1Ah)
Note: Use the Medium Partition page (Page Code 11h) to determine the capacity
in MB of each of the partitions on the tape.
Bytes 05 through 07 – Block Length
This field indicates the length of each logical block, in bytes, when the Fixed bit
is set for the READ, VERIFY, and WRITE commands. Valid values for this field
are 0h to 3C000h (240 KB).
When the Block Length is non-zero, fixed-length block operations are
allowed. For fixed-length blocks, only block sizes that are evenly divisible by
four (that is, they end on a 4-byte boundary) are valid. A block length of 0 is
invalid for fixed-length blocks.
When the Block Length is 0, only variable-length block operations are
allowed.
Note: If the Block Length is 0, the SILI bit in the READ command suppresses
illegal length indications for both underlength and overlength reads. If the
Block Length is non-zero, the SILI bit of the READ command suppresses
illegal length indications only for blocks shorter than requested. See
page 12-2 for more information.
10.3.2
READ-WRITE ERROR RECOVERY PAGE (PAGE CODE 01h)
The Read-Write Error Recovery page returns the error recovery parameters
used by the tape drive during read-write operations.
Bit
Byte
00
7
6
5
3
Reserved
2
1
0
DTE
DCR
Page Code
Page Length
01
02
4
Reserved
TB
RSVD
EER
PER
Read Retry Count
03
04
...
Reserved
07
Write Retry Count
08
09
...
Reserved
11
Byte 00, Bits 5 through 0 – Page Code
The value for this field is 01h, identifying the current page as the Read-Write
Error Recovery page.
10-6
SCSI REFERENCE
1009566-001
10.3 WHAT THE TAPE DRIVE RETURNS
Byte 01 – Page Length
This field indicates the number of bytes in the Read-Write Error Recovery page
that follow this byte. The valid value for this field is 0Ah.
Byte 02, Bit 5 – TB (Transfer Block)
The TB bit is not supported by the tape drive. The valid value for this bit is 0.
Byte 02, Bit 3 – EER (Enable Early Recovery)
The EER bit is not supported by the tape drive. The valid value for this bit is 0.
Byte 02, Bit 2 – PER (Post Error)
The PER bit is not supported by the tape drive. The valid value for this bit is 0.
Byte 02, Bit 1 – DTE (Disable Transfer on Error)
The DTE bit is not supported by the tape drive. The valid value for this bit is 0.
Byte 02, Bit 0 – DCR (Disable Correction)
The DCR bit is not supported by the tape drive. The valid value for this bit is 0.
Byte 03 – Read Retry Count
This field indicates how many times the tape drive attempts its read recovery
algorithms. If the tape drive fails to reread the block after this number of
attempts, it reports an unrecoverable error. The default value is 05h.
Byte 08 – Write Retry Count
This field indicates how many times the tape drive rewrite a physical block
before reporting an unrecoverable read error. The default value is 05h.
10.3.3
DISCONNECT-RECONNECT PAGE (PAGE CODE 02h)
The Disconnect-Reconnect page returns the parameters that control how the
tape drive disconnects and reconnects during data transfers.
Bit
Byte
7
6
5
4
3
Reserved
00
Page Length
02
Buffer Full Ratio
03
Buffer Empty Ratio
(MSB)
05
06
(MSB)
07
OCTOBER 2008
1
0
Page Code
01
04
2
Bus Inactivity Limit
(LSB)
Disconnect Time Limit
(LSB)
VXA-2 TAPE DRIVE
10-7
CHAPTER 10 MODE SENSE (1Ah)
Bit
Byte
08
7
6
(MSB)
4
3
2
1
0
Connect Time Limit
09
10
5
(MSB)
(LSB)
Maximum Burst Size
11
Reserved
12
(LSB)
DTDC
13
Reserved
14
15
Byte 00, Bits 5 through 0 – Page Code
The value for this field is 02h, identifying the current page as the
Disconnect-Reconnect page.
Byte 01 – Page Length
The value returned for this field is 0Eh, indicating that 14 bytes of data for the
Disconnect-Reconnect page follow this byte.
Byte 02 – Buffer Full Ratio
The tape drive does not support this field. The value returned for this field is 0.
The tape drive manages the data buffer by adjusting the tape speed and by
pausing and resuming tape motion as necessary to match the initiator’s data
transfer rate.
Byte 03 – Buffer Empty Ratio
The tape drive does not support this field. The value returned for this field is 0.
The tape drive manages the data buffer by adjusting the tape speed and by
pausing and resuming tape motion as necessary to match the initiator’s data
transfer rate.
Bytes 04 and 05 – Bus Inactivity Limit
The tape drive does not support this field. The value returned for this field is 0,
indicating that the tape drive may assert the Bsy (Busy) signal for an indefinite
period of time.
Bytes 06 and 07 – Disconnect Time Limit
The tape drive does not support this field. The value returned for this field is 0.
Bytes 08 and 09 – Connect Time Limit
The tape drive does not support this field. The value returned for this field is 0.
10-8
SCSI REFERENCE
1009566-001
10.3 WHAT THE TAPE DRIVE RETURNS
Bytes 10 and 11 – Maximum Burst Size
This field indicates the amount of data, in 512-byte increments, that can be
transferred between the initiator and the tape drive before a disconnect is
required. The tape drive supports all values for this field. The default is 0,
which means that there is no limit to the amount of data that can be
transferred before a disconnect is required.
Byte 12, Bits 1 and 0 – DTDC (Data Transfer Disconnect Control)
This field indicates how the tape drive performs a disconnect. Table 10-5 lists
the valid values for this field.
Table 10-5 Values returned in the MODE SENSE DTDC field
DTDC
Value
Description
00b
Disconnects are not controlled by the DTDC field. Disconnects are controlled by the other
fields on this page. (Power-on default)
01b
Once the data transfer of a command has started, the tape drive should not disconnect until
all of the data has been transferred. The Maximum Burst Size (bytes 10 and 11) must be set
to 0.
10b
Not valid.
11b
Once the data transfer of a command has started, the tape drive should not disconnect until
the command is complete. The Maximum Burst Size (bytes 10 and 11) must be set to 0.
10.3.4
CONTROL MODE PAGE (PAGE CODE 0Ah)
The Control Mode page indicates whether the tape drive returns Check
Condition status when one of its write and read error counters reaches a
specified threshold. For information about using the LOG SELECT command
to set threshold values for the tape drive’s write and read error counters, refer
to Chapter 7.
Bit
Byte
7
6
5
4
RSVD
00
2
1
0
Page Code
Page Length
01
RSVD
02
Queue Algorithm Modifier
03
EECA
04
RLEC
Reserved
Reserved
RAENP
QErr
DQue
UAAENP
EAENP
Reserved
05
06
3
(MSB)
07
OCTOBER 2008
Ready AEN Holdoff Period
(LSB)
VXA-2 TAPE DRIVE
10-9
CHAPTER 10 MODE SENSE (1Ah)
Byte 00, Bits 5 through 1 – Page Code
The value for this field is 0Ah, identifying the current page as the Control
Mode page.
Byte 01 – Page Length
This field indicates the number of bytes in the Control Mode page that follow
this byte. The value returned for this field is 06h.
Byte 02, Bit 0 – RLEC (Report Log Exception Condition)
This field indicates whether the tape drive returns Check Condition status
with the sense key set to Unit Attention (6h) when one of its write and read
error counters reaches a specified threshold, as follows:
0
Unit Attention is not returned when a threshold condition
is met
1
Unit Attention is returned when a threshold condition is
met
Byte 03, Bits 7 through 4 – Queue Algorithm Modifier
The tape drive does not support the Simple Queue Tag message. The value
returned for this field is 0.
Byte 03, Bit 1 – QErr (Queue Error)
The tape drive does not support the Simple Queue Tag message. The value
returned for this field is 0.
Byte 03, Bit 0 – DQue (Disable Queuing)
The tape drive does not support the Simple Queue Tag message. The value
returned for this field is 1.
Byte 04, Bit 7 – EECA (Enable Extended Contingent Allegiance)
The tape drive does not support extended contingent allegiance. The value
returned for this bit is 0.
Byte 04, Bit 2 – RAENP (Ready AEN Permission)
The tape drive does not support asynchronous event notification (AEN). The
value returned for this bit is 0.
Byte 04, Bit 1 – UAAENP (Unit Attention AEN Permission)
The tape drive does not support asynchronous event notification. The valid
value for this bit is 0.
Byte 04, Bit 0 – EAENP (Enable AEN Permission)
The tape drive does not support asynchronous event notification (AEN). The
value returned for this bit is 0.
10-10
SCSI REFERENCE
1009566-001
10.3 WHAT THE TAPE DRIVE RETURNS
Bytes 06 and 07 – Ready AEN Holdoff Period
The tape drive does not support asynchronous event notification. The value
returned for this field is 0.
10.3.5
DATA COMPRESSION PAGE (PAGE CODE 0Fh)
The Data Compression page indicates the parameters used by the tape drive
to control data compression.
Bit
Byte
7
6
5
4
RSVD
00
2
1
Page Length
02
DCE
03
DDE
DCC
Reserved
RED
Reserved
(MSB)
…
Compression Algorithm
(LSB)
07
08
0
Page Code
01
04
3
(MSB)
…
Decompression Algorithm
(LSB)
11
12
…
Reserved
15
Byte 00, Bits 5 through 0 – Page Code
The value for this field is 0Fh, identifying the current page as the Data
Compression page.
Byte 01 – Page Length
The value returned for this field is 0Eh, indicating that 14 bytes of data for the
Data Compression page follow this byte.
Byte 02, Bit 7 – DCE (Data Compression Enable)
This field indicates the current state of data compression, as follows:
OCTOBER 2008
0
Data compression is disabled
1
Data compression is enabled
VXA-2 TAPE DRIVE
10-11
CHAPTER 10 MODE SENSE (1Ah)
Byte 02, Bit 6 – DCC (Data Compression Capable)
The value for this field is 01h, indicating that the tape drive is capable of
compressing data.
Byte 03, Bit 7 – DDE (Data Decompression Enable)
The value returned for this field is 01h, indicating that data decompression is
enabled. The tape drive automatically decompresses compressed data before
sending it to the initiator.
Byte 03, Bits 6 and 5 – RED (Report Exception on Decompression)
The tape drive does not report exceptions on decompression (boundaries
between compressed and uncompressed data). The value returned for this
field is 0.
Bytes 04 through 07 – Compression Algorithm
The value returned for this field is 03h, indicating that the tape drive uses the
ALDC data compression algorithm with a 512-byte buffer to compress data
from the initiator.
Bytes 08 through 11 – Decompression Algorithm
The value returned for this field is 03h, indicating that the tape drive uses the
ALDC data decompression algorithm with a 512-byte buffer to decompress
data from tape.
10.3.6
Bit
Byte
7
6
DEVICE CONFIGURATION PAGE (PAGE CODE 10h)
5
3
Reserved
00
2
RSVD
CAP
CAF
Active Format
Active Partition
04
Write Buffer Full Ratio
05
Read Buffer Empty Ratio
(MSB)
Write Delay Time
07
08
DBR
BIS
10-12
RSmk
AVC
(LSB)
SOCF
RBO
REW
Gap Size
09
10
0
Page Length
03
06
1
Page Code
01
02
4
EOD Defined
SCSI REFERENCE
EEG
SEW
Reserved
1009566-001
10.3 WHAT THE TAPE DRIVE RETURNS
Bit
Byte
11
7
6
5
4
3
2
1
0
(MSB)
Buffer Size at Early Warning
12
(LSB)
13
14
Select Data Compression Algorithm
15
Reserved
Byte 00, Bits 5 through 0 – Page Code
The value for this field is 10h, identifying the current page as the Device
Configuration page.
Byte 01 – Page Length
The value returned for this field is 0Eh, indicating that 14 bytes of additional
data for the Device Configuration page follow this byte.
Byte 02, Bit 6 – CAP (Change Active Partition)
The value returned for this bit is always 0.
Byte 02, Bit 5 – CAF (Change Active Format)
The value returned for this bit is always 0.
Byte 02, Bits 4 through 0 – Active Format
The tape drive does not support this field. The value returned for this field is 0.
Byte 03 – Active Partition
This field indicates the number of the partition in which the tape is currently
positioned, as follows:
n – The tape is positioned at partition n, where n is either 0 or 1. Note that
partitions are numbered consecutively from the end of the tape. Partition 0
is always the last partition on the tape.
Notes:
If the tape is not partitioned, the value in the Active Partition field is always 0.
If the CAP bit is 0, the tape drive ignores the Active Partition byte.
If you specify a partition that does not exist, the tape drive returns Check
Condition status with the sense key set to Illegal Request.
If the tape drive is not ready, the value of the Active Partition field returned in
the MODE SENSE data may be invalid.
OCTOBER 2008
VXA-2 TAPE DRIVE
10-13
CHAPTER 10 MODE SENSE (1Ah)
Byte 04 – Write Buffer Full Ratio
The tape drive does not support this field. The value returned for this field is 0.
The tape drive manages the data buffer by adjusting the tape speed and by
pausing and resuming tape motion as necessary to match the initiator’s data
transfer rate.
Byte 05 – Read Buffer Empty Ratio
The tape drive does not support this field. The value returned for this field is 0.
The tape drive manages the data buffer by adjusting the tape speed and by
pausing and resuming tape motion as necessary to match the initiator’s data
transfer rate.
Bytes 06 and 07 – Write Delay Time
If a WRITE command completes without transferring enough data to exceed
the value specified for the Write Buffer Full Ratio, the value returned in this
field indicates the maximum amount of time, in units of 100 msec, that the
data will remain in the buffer. When the time specified by Write Delay Time
elapses, the data in the buffer is written to tape.
Valid values for this field are 0000h to FFFFh. The default value for this field is
0000h. Any value greater than 1999h (approximately 11 minutes) is
automatically set to 1999h.
Byte 08, Bit 7 – DBR (Data Buffer Recovery)
The tape drive does not support the DBR bit. The value returned for this bit
is 0.
Byte 08, Bit 6 – BIS (Block Identifier Supported)
The value returned for this bit is 1, indicating that block IDs are written on the
tape relative to each partition.
Byte 08, Bit 5 – RSmk (Report Setmarks)
This field indicates whether the tape drive returns Check Condition status
when it encounters a setmark on the tape during read, verify, space block, or
space filemark operations, as follows:
0
Do not report setmarks (setmarks are ignored)
1
Report setmarks (default setting)
Byte 08, Bit 4 – AVC (Automatic Velocity Control)
The value returned for this bit is always 1, indicating that the tape drive’s
intelligent velocity control is always enabled.
Byte 08, Bits 3 and 2 – SOCF (Stop on Consecutive Filemarks)
The tape drive does not support the SOCF field. The valid value for this field
is 0.
10-14
SCSI REFERENCE
1009566-001
10.3 WHAT THE TAPE DRIVE RETURNS
Byte 08, Bit 1 – RBO (Recover Buffer Order)
The tape drive does not support the RBO bit. The valid value for this bit is 0.
Byte 08, Bit 0 – REW (Report Early Warning)
This field indicates whether reporting of the early-warning condition
(approaching LEOP) during a read operation is enabled or disabled, as follows:
0
Early-warning condition is not reported for read
operations; early-warning condition is reported for write
operations (default setting).
1
Early-warning condition is reported after completing the
current READ or WRITE command.
The tape drive reports an early-warning condition as a Check Condition status
with the sense key set to No Sense. The EOM bit is set to 1 and the LBOT bit is
set to 0 in the extended sense data.
Byte 09 – Gap Size
The tape drive does not support the Gap Size field. The valid value for this
field is 0.
Byte 10, Bits 7 through 5 – EOD Defined
The tape drive does not support the EOD field. The valid value for this field
is 0.
Byte 10, Bit 4 – EEG (Enable EOD Generation)
The tape drive does not support this field. The value returned for this field is 0.
Byte 10, Bit 3 – SEW (Synchronize at Early Warning)
The value returned for this bit is 1, indicating that the tape drive writes any
buffered data to the tape when the early-warning condition (approaching
LEOP) is detected during a write operation.
Bytes 11 through 13 – Buffer Size at Early Warning
The tape drive does not support the Buffer Size at Early Warning field. The
valid value for this field is 0.
Byte 14 – Select Data Compression Algorithm
The tape drive does not support selecting the Data Compression Algorithm.
The value returned for this field is 0.
OCTOBER 2008
VXA-2 TAPE DRIVE
10-15
CHAPTER 10 MODE SENSE (1Ah)
10.3.7
MEDIUM PARTITION PAGE (PAGE CODE 11h)
The Medium Partition page indicates how the currently loaded tape is
partitioned.
Bit
Byte
7
6
5
4
3
Reserved
00
Page Length
02
Maximum Additional Partitions
03
Additional Partitions Defined
FDP
SDP
IDP
PSUM
05
Medium Format Recognition
06
Reserved
07
Reserved
08
(MSB)
0
Reserved
Partition Size (Partition 0)
09
10
1
Page Code
01
04
2
(MSB)
(LSB)
Partition Size (Partition 1)
11
(LSB)
12
...
Partition Size (Partitions 2 through 63)
135
Byte 00, Bits 5 through 0 – Page Code
The value for this field is 11h, identifying the current page as the Medium
Partition page.
Byte 01 – Page Length
The value returned for this field is 86h, indicating that 134 bytes of additional
data for the Medium Partition page follow this byte.
Byte 02 – Maximum Additional Partitions
The value returned for this field is 01h, indicating that one partition in
addition to the original partition (the entire tape) can be defined on the
current tape.
Byte 03 – Additional Partitions Defined
The value returned for this field is either 00h (the tape contains one partition
comprised of the entire tape) or 01h (one additional partition).
10-16
SCSI REFERENCE
1009566-001
10.3 WHAT THE TAPE DRIVE RETURNS
Byte 04, Bit 7 – FDP (Fixed Data Partitions)
The value returned for this field is always of 0.
Byte 04, Bit 6 – SDP (Select Data Partitions)
The value returned for this field is always of 0.
Byte 04, Bit 5 – IDP (Initiator Defined Partitions)
The value returned for this field is always of 0.
Byte 04, Bits 4 and 3 – PSUM (Partition Size Unit of Measure)
The value returned for this field is always 10b, indicating that partition sizes
are specified in megabytes (MB).
Byte 05 – Medium Format Recognition
The value returned for this field 03h, indicating that the tape drive can
recognize both medium format and partition information.
Bytes 08 and 09 – Partition 0 Size
The value returned for this field is the size, in MB, of partition 0 on the
currently loaded tape. If the tape contains just a single partition, the Partition
Size (partition 0) field returns the approximate uncompressed capacity of the
entire tape.
Bytes 10 and 11 – Partition 1 Size
This field indicates the size, in MB, of partition 1 on the currently loaded tape
and represents approximate amount of uncompressed data space that is
available between the logical beginning of partition 1 (LBOP) and the logical
end of partition 1 (LEOP) on the tape.
Bytes 12 through 135 – Partition Size (Partitions 2 through 63)
The tape drive does not support more than two partitions. The tape drive
returns a value of 0 for each of these two-byte fields.
10.3.8
TAPEALERT PAGE (PAGE CODE 1Ch)
The TapeAlert page indicates how the TapeAlert function is configured.
Bit
Byte
00
7
6
5
03
OCTOBER 2008
3
Reserved
2
1
0
RSVD
LogErr
Page Code
Page Length
01
02
4
Perf
Reserved
Reserved
DExcpt
Test
MRIE
VXA-2 TAPE DRIVE
10-17
CHAPTER 10 MODE SENSE (1Ah)
Bit
Byte
7
6
5
4
3
2
1
0
04
...
Interval Timer
07
08
...
Test Flag Number
11
Byte 00, Bits 5 through 0 – Page Code
The value for this field is 1Ch, which identifies the current page as the
TapeAlert page.
Byte 01 – Page Length
The value returned for this field is 0Ah, indicating that 14 bytes of additional
data for the TapeAlert page follow this byte.
Byte 02, Bit 7 – Perf (Performance)
This field indicates whether logging of informational exception operations that
can cause delays are acceptable, as follows:
0
Delays due to logging are not allowed (default setting)
1
Delays due to logging are allowed
Byte 02, Bit 3 – DExcpt (Disable Exception Reporting)
This field indicates how the tape drive handles the reporting of informational
exception operations, as follows:
10-18
SCSI REFERENCE
0
The tape drive reports informational exceptions using the
method specified by the MRIE field
1
The tape drive disables all informational exception
operations
The MRIE field is ignored (default setting)
1009566-001
10.3 WHAT THE TAPE DRIVE RETURNS
Byte 02, Bit 2 – Test
This field indicates whether the tape drive performs the TapeAlert test
specified in the Test Flag Number field, as follows:
0
The tape drive does not generate any false informational
exception conditions
1
The tape drive generates a false informational exception
condition based on the Test Flag Number field (default
setting)
Byte 02, Bit 0 – LogErr
The tape drive does not support the LogErr bit. The value returned for this bit
is 0.
Byte 03, Bits 3 through 0 – MRIE (Method of Reporting Exception
Information)
This field indicates the method used by the tape drive to report informational
exception conditions. Table 10-6 lists the valid values for MRIE.
Table 10-6 Valid values for MRIE in the MODE SELECT command
MRIE
Description
0h
Do not report informational exceptions.
2h
Generate a Check Condition status with the sense key set to Unit Attention (6h).
3h
Generate a Check Condition status with the sense key set to Recovered Error (01h), if the
reporting of recovered errors is allowed. Since the tape drive does not support the PER bit (see
page 10-6), this setting has the same effect as setting MRIE to 0h.
4h
Generate a Check Condition status with the sense key set to Recovered Error (01h), regardless
of the PER bit.
5h
Generate a Check Condition status with the sense key set to No Sense (00h).
6h
Report informational exceptions only in response to an unsolicited REQUEST SENSE command.
Bytes 04 through 07 – Interval Timer
The tape drive does not support this field. The value returned for this field is 0.
OCTOBER 2008
VXA-2 TAPE DRIVE
10-19
CHAPTER 10 MODE SENSE (1Ah)
Bytes 08 through 11 – Test Flag Number
The value in this field indicates what action the tape drive should take if the
Test bit is set to 1, as follows:
Table 10-7 Test Flag Number settings for MODE SENSE
Test Flag Number Description
0
Generate a false information exception condition.
1 through 64
–1 through –64
Clear the TapeAlert Flag indicated by the number.
Set all supported TapeAlert Flags. See Table 8-6 on
page 8-11 for a list of the supported TapeAlert Flags.
32767
10.3.9
Set the TapeAlert Flag indicated by the number and process.
VENDOR UNIQUE PARAMETERS PAGE 1 (PAGE CODE 21h)
The Vendor Unique Parameters Page 1 page is used to report the settings for
tape drive options that are unique to Tandberg Data.
Bit
Byte
00
7
6
5
4
3
Reserved
2
1
0
QueLoad
NoNegR
Page Code
Page Length
01
02
Reserved
03
04
Reserved
ChkClnRq
05
SOPR
DfNoCmp
Reserved
ExInq
RSVD
ServReq
FvCpcty
NoSvPtr
RespDuringImmed
Byte 00, Bits 5 through 0 – Page Code
The value for this field is 21h, identifying the current page as the Vendor
Unique Parameters Page 1 page.
Byte 01 – Page Length
The value returned for this field is 04h, indicating that 4 bytes of additional data
for the Vendor Unique Parameters Page 1 page follow this byte.
10-20
SCSI REFERENCE
1009566-001
10.3 WHAT THE TAPE DRIVE RETURNS
Byte 04, Bit 6 – ChkClnRq (Check Condition on Cleaning Required)
This field indicates whether the device sends a Check Condition for a single
SCSI command after it is determined that a cleaning cartridge use is necessary.
0b
Do not send Check Condition for SCSI command when
cleaning cartridge use is required
1b
Send Check Condition for SCSI command when cleaning
cartridge use is required
This field is kept in non-volatile RAM, and once set, remains in effect even
between power-on cycles, until the value has been changed by this command.
Byte 04, Bit 2 – ServReq (Service Required)
This field indicates whether the device requires servicing before normal
operations may be resumed.
0b
Service is required, normal operations may not be allowed
1b
Service is not required, normal operations are allowed
This field is kept in non-volatile RAM, and once set, remains in effect, even
between power-on cycles, until the tape drive is serviced or the value has been
changed by this command.
Byte 04, Bit 1 – QueLoad (Queue Load Command During Load)
This field indicates whether the tape drive will queue a LOAD command
received while the tape drive is performing an automatic cartridge load.
0b
Report busy for LOAD command during autoload
1b
Queue LOAD command during autoload
The value for this field is stored in nonvolatile memory and remains in effect
through power cycles, until changed again by the MODE SELECT command.
Byte 04, Bit 0 – NoNgRs (No Negative Residuals)
This bit indicates whether the tape drive reports residual values on backward
space operations as positive or negative (2’s compliment) numbers, as follows:
0b
Report residuals as negative numbers (2’s complement)
(default setting)
1b
Report residuals as positive numbers
The value for this field is stored in nonvolatile memory and remains in effect
through power cycles.
OCTOBER 2008
VXA-2 TAPE DRIVE
10-21
CHAPTER 10 MODE SENSE (1Ah)
Byte 05, Bit 7 – SOPR (SCSI Operating Parameter Restoration)
This bit indicates whether the tape drive should restore SCSI operating
parameters (the settings for synchronous/asynchronous transfers,
narrow/wide transfers, transfer rate, and offset for synchronous transfers)
when it detects that its firmware has been updated.
0b
Do not restore SCSI operating parameters after a firmware
update (default setting)
1b
Restore the SCSI operating parameters after a firmware
update
The value for this field is stored in nonvolatile memory and remains in effect
through power cycles.
Byte 05, Bit 6 – DfNoCmp (Default No Compression)
This bit indicates whether the tape drive should permanently default to
having write compression disabled at power up.
0b
Permanently default to compression enabled (default
setting)
1b
Permanently default to compression disabled
The value for this field is stored in nonvolatile memory and remains in effect
through power cycles.
Byte 05, Bit 5 – ExInq (Extended Inquiry Overwrite)
This bit indicates whether the tape drive permanently overwrites an extended
area of the Standard Inquiry data when the SEND DIAGNOSTIC Set Inquiry
Data page (86h) is sent to the tape drive, as follows:
0b
Permanently overwrite only the Vendor Identification and
Product Identification fields (bytes 8 through 31) of the
Standard Inquiry Data (default setting)
1b
Permanently overwrite the Product Revision Level and
four bytes of Vendor Specific data (bytes 32 through 39) in
addition to the Vendor Identification and Product
Identification fields in the Standard Inquiry Data
The value for this field is stored in nonvolatile memory and remains in effect
through power cycles.
10-22
SCSI REFERENCE
1009566-001
10.3 WHAT THE TAPE DRIVE RETURNS
Byte 05, Bit 3 – FvCpcty (Favor Capacity)
This bit indicates whether the tape drive favors tape capacity over write speed
when managing the data buffer during a write operation, as follows:
0b
Favors write speed over capacity (default setting)
1b
Favors capacity (the amount of data that can be written to
tape) over write speed
The value for this field is stored in nonvolatile memory and remains in effect
through power cycles.
Byte 05, Bit 2 – NoSvPtr (No Save Pointer on Read)
This bit indicates whether the tape drive should omit the Save Data Pointer
message when disconnecting from the SCSI bus during a read operation, as
follows:
0b
Send a Save Data Pointer message before sending a
Disconnect message during a read operation (default
setting)
1b
Omit the Save Data Pointer message before sending a
Disconnect message during a read operation
The value for this field is stored in nonvolatile memory and remains in effect
through power cycles.
Byte 05, Bits 1 and 0 – RespDuringImmed (Response During Immediate)
This field indicates how the tape drive responds to a motion command
received while the tape drive is busy completing an immediate command (for
example, LOAD, LOCATE). Table 10-8 lists the valid values for this field.
Table 10-8 Valid values for RespDuringImmed in the MODE SENSE command
RespDuringImmed Description
Value
OCTOBER 2008
00b
Return Busy status. (default setting)
01b
Return Check Condition status. The sense key is set to 2h
(Not Ready) with and ASC of 04h and an ASCQ of 01.
10b
Queue the command until the immediate command is
complete. If a second command is received, return Busy
status.
11b
Reserved
VXA-2 TAPE DRIVE
10-23
CHAPTER 10 MODE SENSE (1Ah)
10.3.10 VENDOR UNIQUE PARAMETERS PAGE 2 (PAGE CODE 22h)
The Vendor Unique Parameters Page 2 page is used to report the configuration
information for a tape drive that is unique to Tandberg Data.
Bit
Byte
00
7
6
5
4
Reserved
2
1
0
Page Code
Page Length
01
02
3
Reserved
LVD Config
Interface
SCSI ID Jumpers
03
Reserved
Wide
04
...
Reserved
09
Byte 00, Bits 5 through 0 – Page Code
The value for this field is 22h, identifying the current page as the Vendor
Unique Parameters Page 2 page.
Byte 01 – Page Length
This field indicates the number of bytes in the Vendor Unique Parameters
Page 2 page that follow this byte. The value returned for this field is 08h (8 bytes).
Byte 02, Bits 4 through 5 – LVD Config
This field indicates the LVD chip’s Differential Sense receiver’s configuration.
It is only valid if the Interface field is 1 (LVD SCSI) or 3 (SCSI-3).
0
LVD (Low Voltage Differential)
1
SE (Single Ended)
2
HVD (High Voltage Differential)
3
Unknown or Invalid
Byte 02, Bits 0 through 3 – Interface
This field indicates the type of interface found on the tape drive.
10-24
SCSI REFERENCE
0
Single Ended Narrow SCSI
1
LVD SCSI
2
ATAPI
3
SCSI-3
1009566-001
10.4 EXCEPTIONS AND ERROR CONDITIONS
Byte 03, Bits 4 through 7 – SCSI ID Jumpers
This field indicates the tape drive’s SCSI ID as set using the tape drive SCSI ID
jumpers. The valid values are 00h through 0Fh (0 through 15).
Byte 03, Bit 0 – Wide
This field indicates whether the tape drive is connected to a wide SCSI bus, as
follows:
0b
The tape drive is not connected to a wide bus (that is, it is
connected to an 8-bit, narrow SCSI bus)
1b
The tape drive is connected to a wide bus (that is, it is
connected to a 16-bit, wide SCSI bus)
10.4 EXCEPTIONS AND ERROR CONDITIONS
Table 10-9 lists the exceptions and error conditions that cause the tape drive to
return Check Condition status for the MODE SENSE command.
Table 10-9 REQUEST SENSE data for MODE SENSE command errors and exceptions
Sense
Key
ASC
ASCQ Description
(Byte 12) (Byte 13)
5h
24h
00h
Illegal Request. Invalid field in the CDB.The Page Code is invalid.
5h
39h
00h
Illegal Request. The Page Control field is set to 11b (return saved
parameters). The tape drive does not support saving parameters.
OCTOBER 2008
VXA-2 TAPE DRIVE
10-25
CHAPTER 10 MODE SENSE (1Ah)
Notes
10-26
SCSI REFERENCE
1009566-001
11
PREVENT/ALLOW MEDIUM
REMOVAL (1Eh)
Bit
Byte
7
6
5
4
3
2
1
0
00
0
0
0
1
1
1
1
0
01
Logical Unit Number
Reserved
02
Reserved
03
Prevent
04
Control
05
11.1 ABOUT THIS COMMAND
You can use the PREVENT/ALLOW MEDIUM REMOVAL command to allow
or prevent the removal of the data cartridge from the tape drive.
The PREVENT/ALLOW MEDIUM REMOVAL command is reservation
independent. The tape drive will execute a PREVENT/ALLOW MEDIUM
REMOVAL command issued by any initiator even if the tape drive is reserved
by another initiator.
If an initiator has issued a PREVENT MEDIUM REMOVAL (1Eh) command to
prevent the removal of the data cartridge, the data cartridge will not be ejected
until that initiator sends an ALLOW MEDIUM REMOVAL command to allow
the data cartridge to be removed.
If more than one initiator has issued PREVENT MEDIUM REMOVAL
commands to the tape drive to prevent the removal of the data cartridge, the
cartridge will not be ejected until each of those initiators sends an ALLOW
MEDIUM REMOVAL command to release the condition.
OCTOBER 2008
VXA-2 TAPE DRIVE
11-1
CHAPTER 11 PREVENT/ALLOW MEDIUM REMOVAL (1Eh)
Effect on the Unload Button
When removal of the data cartridge is prevented by the PREVENT/ALLOW
MEDIUM REMOVAL command, the tape drive’s eject button is disabled;
pressing this button does not cause the tape to be rewound or ejected.
Effect on the LOAD/UNLOAD (1Bh) Command
When removal of the data cartridge is prevented by the PREVENT/ALLOW
MEDIUM REMOVAL command, issuing a LOAD/UNLOAD (1Bh) command
causes the tape to be unloaded from the tape path but not ejected from the
tape drive. Any data in the buffer is written to tape before the tape is rewound
and unloaded from the tape path.
11.2 CDB FIELD DEFINITIONS
Logical Unit Number (LUN) – Byte 01, Bits 7 through 5
The tape drive only supports LUN 0. The value for this field must be 0.
Byte 04, Bit 0 – Prevent
This field specifies whether the tape drive prevents or allows the removal of a
data cartridge from the tape drive, as follows:
0
Allow the data cartridge to be removed
1
Prevent the data cartridge from being removed
The prevent-data-cartridge-removal condition terminates when any of the
following conditions occur:
A PREVENT/ALLOW MEDIUM REMOVAL command with the Prevent bit
set to 0 is received from all initiators that set the prevent condition.
The tape drive is reset by a Bus Device Reset message, SCSI bus reset, or
power-on reset.
11-2
SCSI REFERENCE
1009566-001
12
READ (08h)
Bit
Byte
7
6
5
4
3
2
1
0
00
0
0
0
0
1
0
0
0
SILI
Fixed
Logical Unit Number
01
02
Reserved
(MSB)
Transfer Length
03
(LSB)
04
Control
05
12.1 ABOUT THIS COMMAND
The READ command transfers one or more bytes or blocks of data from the
tape drive to the initiator, beginning with the next logical block. The tape drive
reads tapes written in VXA-1 or VXA-2 formats, and automatically determines
the format of the data on the tape.
Notes:
The tape drive can read tapes that have a combination of fixed-length and
variable-length data blocks.
The tape drive will report the early-warning condition (LEOP reached) if the
REW bit is set with the MODE SELECT command (byte 8, bit 0 in the Device
Configuration page).
Unexpected events, such as encountering filemarks or EOT, cause the data
transfer to stop.
If the disconnects are allowed, the tape drive may disconnect from the initiator.
12.2 CDB FIELD DEFINITIONS
Logical Unit Number (LUN) – Byte 01, Bits 7 through 5
The tape drive only supports LUN 0. The value for this field must be 0.
OCTOBER 2008
VXA-2 TAPE DRIVE
12-1
CHAPTER 12 READ (08h)
Byte 01, Bit 1 – SILI (Suppress Illegal Length Indication)
The SILI bit is used to suppress an illegal length Check Condition status for
read operations that read logical blocks that do not contain the defined
number of bytes. This bit is valid only when the read operation is for
variable-length logical blocks (that is, when the Fixed bit is set to 0).
0
Do not suppress illegal length indication Check Condition
status
1
Suppress illegal length indication Check Condition status
Notes:
If the Fixed bit is 1 (fixed-length logical blocks) and the SILI bit is 1, the tape
drive returns Check Condition status with the sense key set to Illegal Request
(5h). The ASC and ASCQ fields are set to 24h and 00h.
If the Fixed bit is 0 and the SILI bit is 1, Check Condition status is suppressed
for all cases in which the length of the logical block to be read is less than the
length specified by the Transfer Length field. If the length of the logical block
is greater than the length specified by the Transfer Length field, Check
Condition status is suppressed only if the Block Length field of the MODE
SELECT Block Descriptor is 0.
The tape drive never transfers more data than requested, regardless of the
setting of the SILI bit.
Byte 01, Bit 0 – Fixed
The Fixed bit defines the type of read operation to be performed, as follows:
0
Read a single logical block
The length of this block is specified in the Transfer Length
field.
1
Read one or more fixed-length logical blocks
The number of blocks is specified in the Transfer Length
field.
Note: The tape drive returns Check Condition status with the sense key set to
Illegal Request (5h) if the Fixed field in the READ command is 1
(fixed-length logical blocks) and the Block Length field in the current
MODE SELECT data is 0 (variable-length logical block). The ASC and
ASCQ bits are set to 81h and 00h (fixed/variable mismatch).
Bytes 02 through 04 – Transfer Length
The Transfer Length field specifies the amount of data to be read, as follows:
12-2
SCSI REFERENCE
1009566-001
12.3 EXCEPTIONS AND ERROR CONDITIONS
When the Fixed bit is set to 0 (read variable-length blocks), this field contains
the length of the logical block in bytes. The logical block can be any size from
1 byte to 240 KB (1 KB = 1,024 bytes). The valid value for this field is from
000001h to 03C000h.
When the Fixed bit is set to 1 (read fixed-length blocks), this field contains
the number of logical blocks to be read. The length of each block is either the
power-on default block length or the length specified with the currently
active MODE SELECT command (see page 9-5). Only fixed-length blocks
with a size that is evenly divisible by 4 are allowed.
The data is read from the next logical block on the tape and is transferred to
the initiator.
Note: When the value for the Transfer Length field is 0, no data is transferred and
the current position of the tape is not changed. A value of 0 for these bytes
is not an error.
12.3 EXCEPTIONS AND ERROR CONDITIONS
The following sections describe exceptions and error conditions that cause the
tape drive to return Check Condition status for the READ command.
12.3.1
TRANSFER LENGTH INCORRECT
If the actual transfer length does not match the requested transfer length, the
information reported depends on the setting of the Fixed bit. (The Check
Condition status may be suppressed if the SILI bit is set to 1.)
The REQUEST SENSE data is set as follows:
OCTOBER 2008
Valid
1
ILI
1
Sense Key
No Sense (0h)
Information
bytes
ƒ If the Fixed bit is 0, indicate the difference between the
requested transfer length and the actual number of
logical blocks read. The result may be a negative value,
which will be expressed in 2’s complement format (see
information beginning on page 9-25 for a definition of
2’s complement).
ƒ If the Fixed bit is 1, indicate the number of blocks
requested, but not transferred.
ASC
00h
ASCQ
00h
FSC
49h
VXA-2 TAPE DRIVE
12-3
CHAPTER 12 READ (08h)
When the READ command terminates in variable mode, the tape is positioned
after the block with the incorrect length (at the start of the next logical block).
When the READ command terminates in fixed mode, the tape is positioned
after the block with the incorrect length (at the start of the next logical block).
Filemark Detected
The tape drive detected a filemark before completing the read operation. The
REQUEST SENSE data is set as follows:
Valid
1
Filemark
1
Sense Key
No Sense (0h)
Information
bytes
Indicate the difference between the number of bytes or
blocks requested and the number of bytes or blocks
actually transferred.
ASC
00h
ASCQ
01h (Filemark Detected)
FSC
41h
When the READ command terminates, the logical position is at the EOT side
of the filemark encountered.
Setmark Detected
The RSmk bit in the MODE SELECT Device Configuration page (Page
Code 10h) is set to 1 and the tape drive detected a setmark before completing
the read operation. The REQUEST SENSE data is set as follows:
Valid
1
Filemark
1
Sense Key
No Sense (0h)
Information
bytes
Indicate the difference between the number of bytes or
blocks requested and the number bytes or blocks actually
transferred.
ASC
00h
ASCQ
03h (Setmark Detected)
FSC
40h
When the READ command terminates, the logical position is at the EOT side
of the setmark encountered.
12-4
SCSI REFERENCE
1009566-001
12.3 EXCEPTIONS AND ERROR CONDITIONS
PEOT or PEOP Encountered
During a read operation, the tape drive encountered the physical end of tape
(PEOT) or the physical end of partition (PEOP). The REQUEST SENSE data is
set as follows:
Valid
1
EOM
1
Sense Key
Volume Overflow (0Dh)
Information
bytes
Indicate the difference between the number of bytes or
blocks requested and the actual number of bytes or blocks
actually transferred.
ASC
00h
ASCQ
02h (PEOT or PEOP Detected)
FSC
2Ah, 2Dh
When the READ command terminates, the logical position is undefined.
EOD Detected
The tape drive detected the EOD mark during the read operation. The
REQUEST SENSE data is set as follows:
Valid
1
Sense Key
Blank Check (8h)
Information
bytes
Indicate the difference between the number of bytes or
blocks requested and the actual number of bytes or blocks
actually transferred.
ASC
00h
ASCQ
05h (EOD Detected)
PEOT
0
FSC
08h
When the READ command terminates, the logical position is after the last
recorded data block, filemark, or setmark.
OCTOBER 2008
VXA-2 TAPE DRIVE
12-5
CHAPTER 12 READ (08h)
Unrecoverable Read Error
An unrecoverable read error occurred before the operation completes and the
tape drive terminated the READ command. The REQUEST SENSE data is set
as follows:
Valid
1
Sense Key
Medium Error (3h) or Hardware Error (4h)
Information
bytes
Indicate the difference between the number of bytes or
blocks requested and the actual number of bytes or blocks
actually transferred.
ASC
11h
ASCQ
00h (Unrecovered Read Error)
FSC
30h, 33h
When the READ command is terminated, the tape drive is positioned after the
unrecovered block.
Note: In both fixed and variable block modes, the tape drive may have entered
the Data Phase before reporting this error.
12.3.2
ADDITIONAL ERRORS
Table 12-1 lists additional exceptions and error conditions that cause the tape
drive to return Check Condition status for the READ command.
Table 12-1 REQUEST SENSE data for READ command errors and exceptions
Sense
Key
ASC
ASCQ Description
(Byte 12) (Byte 13)
2h
04h
01h
Not Ready. In the process of becoming ready. The tape drive is in the
process of initializing itself.
02h
04h
02h
Not Ready. Tape drive is not ready because it is in the process of
ejecting a cartridge.
2h
04h
03h
Not Ready. Manual intervention required. The tape drive requires
manual intervention.
2h
3Ah
00h
Not Ready. Medium not present. The command requires a tape and
no tape is present.
3h
30h
02h
Medium Error. Incompatible format. The format of the currently
loaded tape is not compatible with the tape drive or the tape drive
firmware.
0h
31h
00h
Medium Error. Medium format corrupted. The format of the currently
loaded tape is corrupted.
12-6
SCSI REFERENCE
1009566-001
12.3 EXCEPTIONS AND ERROR CONDITIONS
Table 12-1 REQUEST SENSE data for READ command errors and exceptions (continued)
Sense
Key
ASC
ASCQ Description
(Byte 12) (Byte 13)
4h
11h
02h
Hardware Error. Error too long to correct. A CRC error was detected
by the decompression hardware. Use the following steps to recover
from this error:
ƒ Reissue the failed command or command sequence.
ƒ Power the tape drive off and back on again.
or
Send a SCSI bus reset (“hard” reset).
ƒ If the error persists, the tape may be bad or the tape drive may require
service.
4h
15h
01h
Hardware Error. Mechanical positioning error. The tape drive cannot
properly position the media.
5h
24h
00h
Illegal Request. Invalid field in the CDB.
ƒ Both the Fixed and SILI bits are set to 1.
ƒ Invalid field in the CDB. The Transfer Length exceeds 3C00h (240 KB)
for a variable-block read.
6h
30h
00h
Unit Attention. Incompatible medium installed. The currently loaded
tape is incompatible with the tape drive.
OCTOBER 2008
VXA-2 TAPE DRIVE
12-7
CHAPTER 12 READ (08h)
Notes
12-8
SCSI REFERENCE
1009566-001
13
READ BLOCK LIMITS (05h)
Bit
Byte
7
6
5
4
3
2
1
0
00
0
0
0
0
0
1
0
1
01
Logical Unit Number
Reserved
02
Reserved
03
04
Control
05
13.1 ABOUT THIS COMMAND
The READ BLOCK LIMITS command requests that the tape drive return data
identifying the maximum and minimum logical block lengths supported. The
data returned by the READ BLOCK LIMITS command applies to both the
variable and fixed block lengths for the READ and WRITE commands.
13.2 CDB FIELD DEFINITIONS
Logical Unit Number (LUN) – Byte 01, Bits 7 through 5
The tape drive only supports LUN 0. The value for this field must be 0.
OCTOBER 2008
VXA-2 TAPE DRIVE
13-1
CHAPTER 13 READ BLOCK LIMITS (05h)
13.3 WHAT THE TAPE DRIVE RETURNS
The tape drive returns Read Block Limits data to the initiator to indicate the
maximum and minimum block lengths it supports, formatted as follows:
Bit
Byte
7
6
5
4
2
0
(MSB)
Maximum Block Length
02
(LSB)
03
04
1
Reserved
00
01
3
(MSB)
Minimum Block Length
05
(LSB)
Bytes 01 through 03 – Maximum Block Length
This field indicates the largest valid logical block length supported by the tape
drive. The value returned is 3C000h (240 KB).
Note: 1 KB = 1,024 bytes.
Bytes 04 and 05 – Minimum Block Length
This field indicates the smallest valid logical block length supported by the
tape drive. The value returned is 00001h (1 byte).
13-2
SCSI REFERENCE
1009566-001
14
READ BUFFER (3Ch)
Bit
Byte
7
6
5
4
3
2
1
0
00
0
0
1
1
1
1
0
0
Logical Unit Number
01
Mode
Buffer ID
02
03
Reserved
(MSB)
Buffer Offset
04
(LSB)
05
06
(MSB)
Allocation Length
07
(LSB)
08
Control
09
14.1 ABOUT THIS COMMAND
The READ BUFFER command is used to read the contents of the tape drive’s
buffer or to return the drive log. When used in concert with the WRITE
BUFFER command, it can be used as a diagnostic tool.
Notes: The data compression setting used during a READ BUFFER command
should be the same as the compression setting used during the WRITE
BUFFER command. That is, if compression was enabled when the data
was written to the buffer, the data should be read in exactly the same
format, using the same Allocation Length and Buffer Offset. If different
values are used, a decompression error may result and the data may not
be read correctly.
A READ BUFFER used without a preceding mirror WRITE BUFFER should
always be done with compression off.
OCTOBER 2008
VXA-2 TAPE DRIVE
14-1
CHAPTER 14 READ BUFFER (3Ch)
14.2 CDB FIELD DEFINITIONS
Logical Unit Number (LUN) – Byte 01, Bits 7 through 5
The tape drive only supports LUN 0. The value for this field must be 0.
Byte 01, Bits 2 through 0 – Mode
The Mode field specifies the type of data to be returned to the initiator.
Table 14-1 lists the valid values for this field.
Table 14-1 Valid Mode settings for the READ BUFFER command
Mode Setting Description
000b
Combined mode. Return the Buffer Descriptor and the data in the buffer to the initiator.
001b
Read Firmware mode. Copy data from the tape drive’s firmware storage location to the
data buffer and return to the initiator.
Note: Before using the READ BUFFER command in this mode, you must first issue a
MODE SELECT command to turn off data compression (set the DCE bit on the Data
Compression page to 0).
010b
Data mode. Return the data in the buffer.
011b
Buffer Descriptor mode. Return the Buffer Descriptor (described on page 14-3).
Byte 02 – Buffer ID
The Buffer ID field specifies the buffer for which the initiator is requesting
data, as follows:
00h
The tape drive’s data buffer
80h
The diagnostic data buffer (tape drive logs)
If you set the Mode field to 010b and the Buffer ID field to 80h, the tape drive’s
log information is returned. This data can be used by Tandberg Data to
diagnose tape drive problems.
Bytes 03 through 05 – Buffer Offset
The Buffer Offset field indicates the location into the buffer that the read
operation should begin. The valid values for this field are between 0 and the
value specified in the Buffer Capacity of the Read Buffer Descriptor (see
page 14-3).
The tape drive ignores this field if the Mode field is set to 011b (Buffer
Descriptor mode).
14-2
SCSI REFERENCE
1009566-001
14.3 WHAT THE TAPE DRIVE RETURNS
Bytes 06 through 08 – Allocation Length
The Allocation Length field specifies the amount of space, in bytes, that the
initiator has allocated for buffer data returned from the tape drive. The
amount of data returned is the Allocation Length or the total amount of data
in the buffer, whichever is less.
Notes:
For Read Firmware Mode (Mode = 001b) or Data Mode (Mode = 010b), set
Allocation Length to the value specified for the Buffer Capacity minus the Buffer
Offset.
For Buffer Descriptor Mode (Mode = 011b), set the Allocation Length to at least
4 bytes.
14.3 WHAT THE TAPE DRIVE RETURNS
Depending on the setting for the Mode field (byte 1, bits 0 through 2) in the
CDB, the READ BUFFER command returns one of the types of data listed in
Table 14-1.
14.3.1
BUFFER DESCRIPTOR
If you set the Mode field to 001b or 011b, the tape drive returns a four-byte
Buffer Descriptor for the buffer.
Bit
Byte
7
6
4
3
2
1
0
Offset Boundary
00
01
5
(MSB)
Buffer Capacity
02
(LSB)
03
Byte 00 – Offset Boundary
This field indicates the boundary alignment within the selected buffer,
represented as 2nth number of bytes. The value of this field represents the
exponent n. The data buffer has a boundary alignment of 64 (26) bytes, so the
value of n returned in this field is always 6.
Bytes 01 through 03 – Buffer Capacity
This field indicates the size of the buffer in bytes, as follows:
For the Buffer ID 00h, the buffer capacity is 200000h (2,097,152 bytes =
2 MB).
For Buffer ID 80h, the buffer capacity is FFE0h (65,504 bytes).
OCTOBER 2008
VXA-2 TAPE DRIVE
14-3
CHAPTER 14 READ BUFFER (3Ch)
14.4 EXCEPTIONS AND ERROR CONDITIONS
Table 14-2 lists the exceptions and error conditions that cause the tape drive to
return Check Condition status for the READ BUFFER command.
Table 14-2 REQUEST SENSE data for READ BUFFER command errors and exceptions
Sense
Key
4h
5h
14-4
ASC
ASCQ Description
(Byte 12) (Byte 13)
11h
24h
SCSI REFERENCE
02h
Hardware Error. Error too long to correct. A CRC error was detected
by the decompression hardware. Use the following steps to recover
from this error:
ƒ Reissue the failed command or command sequence.
ƒ Power the tape drive off and back on again.
or
Send a SCSI bus reset (“hard” reset).
ƒ If the error persists, the tape may be bad or the tape drive may require
service.
00h
Illegal Request. Invalid field in the CDB.
ƒ The Mode field contains a value other than 000b, 001b, 010b, or
011b.
ƒ The Buffer ID field is not set to 0.
ƒ The value in the Buffer Offset field is greater than the value in the
Buffer Capacity field of the Buffer Descriptor.
ƒ The sum of the values in the Allocation Length plus the Buffer Offset
field is greater than the value returned in the Buffer Capacity field of
the Buffer Descriptor.
1009566-001
15
READ POSITION (34h)
Bit
Byte
00
01
7
6
5
4
3
2
1
0
0
0
1
1
0
1
0
0
Logical Unit Number
Reserved
BT
02
…
Reserved
08
Control
09
15.1 ABOUT THIS COMMAND
The READ POSITION command reports the tape drive’s current logical
position, but does not cause tape motion to occur. As described in Chapter 6,
the READ POSITION command is used with the LOCATE (2Bh) command to
position the tape at a specified logical block address.
15.2 CDB FIELD DEFINITIONS
Logical Unit Number (LUN) – Byte 01, Bits 7 through 5
The tape drive only supports LUN 0. The value for this field must be 0.
Byte 01, Bit 0 – BT (Block Type)
This bit determines the type of block number the tape drive returns to the
initiator. The tape drive ignores this field.
OCTOBER 2008
VXA-2 TAPE DRIVE
15-1
CHAPTER 15 READ POSITION (34h)
15.3 WHAT THE TAPE DRIVE RETURNS
When it completes the READ POSITION command, the tape drive returns
20 bytes of Read Position data to the initiator, formatted as follows:
Bit
Byte
00
7
6
BOP
EOP
5
3
Reserved
2
BPU
1
0
Reserved
Partition Number
01
02
Reserved
03
04
4
(MSB)
…
First Block Location
(LSB)
07
08
(MSB)
…
Last Block Location
(LSB)
11
Reserved
12
13
(MSB)
…
Number of Blocks in Buffer
(LSB)
15
16
(MSB)
…
Number of Bytes in Buffer
(LSB)
19
Byte 00, Bit 7 – BOP (Beginning of Partition)
This field indicates whether the tape is positioned at the beginning of a
partition, as follows:
15-2
SCSI REFERENCE
0
The tape is not positioned at the beginning of a partition
1
For a partitioned tape, the tape is positioned at the logical
beginning of the currently active partition (LBOP)
For a non-partitioned tape, the tape is positioned at LBOT
1009566-001
15.3 WHAT THE TAPE DRIVE RETURNS
Byte 00, Bit 6 – EOP (End of Partition)
This field indicates whether the tape is positioned at the end of a partition, as
follows:
0
The tape is not positioned at the end of a partition
1
For a partitioned tape, the tape is positioned between the
logical end of partition (LEOP) and the physical end of
partition (PEOP) of the currently active partition
For a non-partition tape, the tape is positioned between
LEOT and PEOT
Byte 00, Bit 2 – BPU (Block Position Unknown)
This field indicates whether the block position is known, as follows:
0
The block position is known and the remainder of the
READ POSITION data is valid
1
The block position is not known and cannot be obtained
without tape motion
The remainder of the READ POSITION data is not valid.
Byte 01 – Partition Number
This field indicates the number of the partition in which the tape is currently
located. The valid value for this field is either 0 or 1. The tape drive supports
one partition in addition to partition 0. Partition 0 is always the last partition
on the tape.
Note: If the tape is not partitioned, the tape drive returns a value of 0.
Bytes 04 through 07 – First Block Location
This field indicates the block address associated with the current logical block
position (that is, the logical block address of the next data block to be
transferred between the initiator and the tape drive if a READ or WRITE
command is issued). When using a LOCATE command to search for this
position, specify the value returned for this field as the Block Address in
byte 03 through 06 of the LOCATE CDB.
Note: If a READ POSITION command follows a command that requires
immediate action, the block location returned by this command represents
the expected tape position after the immediate command is completed.
Bytes 08 through 11 – Last Block Location
The Last Block Location field is not supported by the tape drive. The value
returned for this field is 0.
OCTOBER 2008
VXA-2 TAPE DRIVE
15-3
CHAPTER 15 READ POSITION (34h)
Bytes 13 through 15 – Number of Blocks in Buffer
The Number of Blocks in Buffer field is not supported by the tape drive. The
value returned for this field is 0.
Bytes 16 through 19 – Number of Bytes in Buffer
The Number of Bytes in Buffer field is not supported by the tape drive. The
value returned for this field is 0.
15.4 EXCEPTIONS AND ERROR CONDITIONS
Table 15-1 lists exceptions and error conditions that cause the tape drive to
return Check Condition status for the READ POSITION command.
Table 15-1 REQUEST SENSE data for READ POSITION command errors and exceptions
Sense
Key
ASC
ASCQ
(Byte 12) (Byte 13)
Explanation
02h
04h
01h
Not Ready. Tape drive is not ready, but is in process of becoming
ready (rewinding or loading tape).
02h
04h
03h
Not Ready. The tape drive is not ready because it needs manual
intervention.
02h
3Ah
00h
Not Ready. Tape drive is not ready. Command requires a tape, and no
tape is present.
03h
30h
02h
Medium Error. The tape format is incompatible with the tape drive
hardware or microcode.
05h
24h
00h
Illegal Request. Invalid field in the CDB. The BT bit is set to 1.
06h
30h
00h
Unit Attention. Incompatible media was rejected after the cartridge
was inserted.
08h
00h
00h
Blank Check. The media has not been formatted.
15-4
SCSI REFERENCE
1009566-001
16
RECEIVE DIAGNOSTIC
RESULTS (1Ch)
Bit
Byte
7
6
5
4
3
2
1
0
00
0
0
0
1
1
1
0
0
Logical Unit Number
01
Reserved
02
03
Reserved
(MSB)
Allocation Length
04
(LSB)
Control
05
16.1 ABOUT THIS COMMAND
You can use the RECEIVE DIAGNOSTIC RESULTS command to retrieve the
results of the self-test requested by a previous SEND DIAGNOSTIC (1Dh)
command. See Chapter 21 for a description of the self-test.
Note: To ensure that the diagnostic results are up-to-date and accurate, be sure
that the RECEIVE DIAGNOSTIC RESULTS command immediately follows
the SEND DIAGNOSTIC command and that the tape drive is reserved for
the initiator’s exclusive use. If there are any intervening commands
between the SEND DIAGNOSTIC and the RECEIVE DIAGNOSTIC
RESULTS command, the information returned may not be valid.
16.2 CDB FIELD DEFINITIONS
Logical Unit Number (LUN) – Byte 01, Bits 7 through 5
The tape drive only supports LUN 0. The value for this field must be 0.
Bytes 03 and 04 – Allocation Length
This field specifies the number of bytes that the initiator has allocated for the
return of RECEIVE DIAGNOSTICS RESULTS data. The tape drive returns
only one diagnostic page per command.
OCTOBER 2008
VXA-2 TAPE DRIVE
16-1
CHAPTER 16 RECEIVE DIAGNOSTIC RESULTS (1Ch)
Table 16-1 lists the diagnostic pages returned by the RECEIVE DIAGNOSTIC
command and their maximum page lengths. Setting the Allocation Length to 0
indicates that no diagnostic data will be returned and is not an error.
Table 16-1 Maximum page length of each supported RECEIVE DIAGNOSTIC page
Maximum Lengtha
Page Code Page Name
a
00h
Supported Diagnostic Pages page
20h (32 bytes)
F0h
Self Test page
400h (1,024 bytes)
FFh
No Diagnostic Results Available page
04h (4 bytes)
This maximum length value includes the four-byte Diagnostic Parameter header sent with each page.
The tape drive terminates the Data In phase when the number of bytes
specified in the Allocation Length field has been transferred or when all
available data has been transferred to the initiator, whichever is less.
16.3 WHAT THE TAPE DRIVE RETURNS
When the tape drive receives a RECEIVE DIAGNOSTIC RESULTS command,
it returns the results of the previous SEND DIAGNOSTIC command. Each
page of the diagnostic data begins with a four-byte Diagnostic Parameter
Header (bytes 00 through 03), followed by the diagnostic parameters for that
page. The Diagnostic Parameter Header indicates the page code for the
diagnostic parameter data being returned and indicates the total length of the
data to follow.
Bit
Byte
7
6
5
4
3
00
Page Code
01
Reserved
02
(MSB)
Page Length
03
2
1
0
(LSB)
Byte 00 – Page Code
This field identifies the page code of the diagnostic for which the tape drive is
returning data. Table 16-1 lists the valid page codes.
Bytes 02 and 03 – Page Length
This field indicates the total number of bytes that will follow this byte if the
Allocation Length specified in the CDB is sufficient. The value returned for
this field depends on the value of the Page Code field.
16-2
SCSI REFERENCE
1009566-001
16.3 WHAT THE TAPE DRIVE RETURNS
Byte 04 – Diagnostic Parameters
This field contains the data resulting from the diagnostic test indicated by the
Page Code field. The data returned for each diagnostic page is described in the
following sections.
16.3.1
SUPPORTED DIAGNOSTIC PAGES PAGE (PAGE CODE 00h)
When the value of the Page Code field (byte 00) in the Diagnostic Parameter
Header is 00h, the data that follows is the Supported Diagnostic Pages page.
This page lists the page codes for all of the diagnostic pages included in the
data being returned. The value in the Page Length field (bytes 2 and 3) of the
Diagnostic Parameter Header for this page is 0018h (24 bytes).
Note: The page codes listed in the fields marked “Tandberg Data Internal”
contain proprietary information for use by Tandberg Data Engineering
only. No diagnostic data is returned for these pages.
Bit
Byte
7
6
5
4
3
00
Page Code (00h)
01
Reserved
02
(MSB)
2
1
Page Length (0018h)
03
0
(LSB)
Supported Log Pages (Page Code 00h)
04
05
…
Tandberg Data Internal
26
Self Test (Page Code F0h)
27
16.3.2
SELF TEST PAGE (PAGE CODE F0h)
When the value of the Page Code field (byte 00) in the Diagnostic Parameter
Header is F0h, the data that follows contains the results from a self-test request
issued using the SEND DIAGNOSTIC command or from a previous self-test
(or POST), if still available. The value in the Page Length field (bytes 2 and 3) of
the Diagnostic Parameter Header is always 0400h (1,024 bytes).
Bit
Byte
7
6
5
4
3
00
Page Code (95h)
01
Reserved
OCTOBER 2008
2
1
VXA-2 TAPE DRIVE
0
16-3
CHAPTER 16 RECEIVE DIAGNOSTIC RESULTS (1Ch)
Bit
Byte
02
7
6
5
(MSB)
4
3
2
1
Page Length (0400h)
03
0
(LSB)
04
…
Self Test Results
nn
Bytes 4 through nn – Self Test Results
The Self Test Results field contains ASCII text that describes the success or
failure of the component tests run during the self-test. If the length of the
ASCII text is less than 1,024 bytes, the remainder of the field is filled with zeros.
Tandberg Data Technical Support may request that you generate this data and
send it to them for analysis.
16.3.3
NO DIAGNOSTIC RESULTS AVAILABLE PAGE
(PAGE CODE FFh)
When the value of the Page Code field (byte 00) in the Diagnostic Parameter
Header is FFh, no additional data follows. The tape drive returns this page if
there are no diagnostic results available. The tape drive also returns this page
if it has not previously received a SEND DIAGNOSTIC command or if an
intervening command has corrupted the diagnostic data. The value in the
Page Length field (bytes 2 and 3) of the Diagnostic Parameter Header is 0000h
(0000 bytes).
Bit
Byte
7
6
5
4
3
00
Page Code (FFh)
01
Reserved
02
(MSB)
03
16-4
SCSI REFERENCE
Page Length (0000h)
2
1
0
(LSB)
1009566-001
17
RELEASE UNIT (17h)
Bit
Byte
7
6
5
4
3
2
1
0
00
0
0
0
1
0
1
1
1
01
Logical Unit Number
3rdPty
Third Party Device ID
RSVD
02
Reserved
03
04
Control
05
17.1 ABOUT THIS COMMAND
The RELEASE UNIT command releases a tape drive from an initiator’s
exclusive use or, if third-party reservations are in effect, from another SCSI
device’s use. To have effect, the command must be issued by the initiator that
reserved the tape drive with a RESERVE UNIT command.
It is not an error to attempt to release a tape drive that is not currently
reserved by the current initiator, but if the tape drive is reserved by another
initiator, then that reservation remains in effect.
17.2 CDB FIELD DEFINITIONS
Logical Unit Number (LUN) – Byte 01, Bits 7 through 5
The tape drive only supports LUN 0. The value for this field must be 0.
Byte 01, Bit 4 – 3rdPty
This field indicates whether the tape drive is to release a third-party
reservation, as follows:
OCTOBER 2008
0
Do not release the third-party reservation
1
Release the third-party reservation
VXA-2 TAPE DRIVE
17-1
CHAPTER 17 RELEASE UNIT (17h)
Byte 01, Bits 3 through 1 – Third Party Device ID
This field indicates the SCSI ID of the initiator that reserved the tape drive.
The tape drive ignores this field if the initiator is not requesting a third-party
reservation release.
17-2
SCSI REFERENCE
1009566-001
18
REQUEST SENSE (03h)
Bit
Byte
7
6
5
4
3
2
1
0
00
0
0
0
0
0
0
1
1
01
Logical Unit Number
02
Reserved
Reserved
03
04
Allocation Length
05
Control
18.1 ABOUT THIS COMMAND
The REQUEST SENSE command requests that the tape drive transfer sense
data to the initiator.
The sense data is valid for the Check Condition status just presented to the
initiator. The tape drive preserves the sense data for the initiator receiving the
Check Condition status until it is cleared by that initiator. Sense data is cleared
when the tape drive receives any subsequent command other than INQUIRY
(12h) from the initiator that received the Check Condition status.
18.2 CDB FIELD DEFINITIONS
Logical Unit Number (LUN) – Byte 01, Bits 7 through 5
The tape drive only supports LUN 0. The value for this field must be 0.
Byte 04 – Allocation Length
This field specifies the number of bytes that the initiator should allocate for the
returned sense data. The tape drive provides a total of 48 bytes (30h) of sense
data. If you specify an Allocation Length of less than 30h, the returned sense
data is truncated. If the Allocation Length is greater than the amount of data to
be returned, only the number of bytes available are transferred; no additional
data is transferred.
OCTOBER 2008
VXA-2 TAPE DRIVE
18-1
CHAPTER 18 REQUEST SENSE (03h)
18.3 WHAT THE TAPE DRIVE RETURNS
When the tape drive receives a REQUEST SENSE command, it returns
32 bytes of extended sense data if the Allocation Length is sufficient.
Bit
Byte
00
7
6
5
03
3
Valid
2
1
Reserved
FMK
EOM
ILI
RSVD
Sense Key
(MSB)
…
Information
(LSB)
06
Additional Sense Length
07
08
0
Error Code
01
02
4
(MSB)
…
Command Specific Information
(LSB)
11
12
Additional Sense Code (ASC)
13
Additional Sense Code Qualifier (ASCQ)
14
Field Replaceable Unit Code
15
Sense Key Specific Data
16
17
Fault Symptom Code
18
19
Unit Sense
20
21
Command
22
23
(MSB)
Remaining Tape
24
(LSB)
25
26
FSC N-1
27
Command N-1
28
FSC N-2
29
Command N-2
30
FSC N-3
31
Command N-3
18-2
SCSI REFERENCE
1009566-001
18.3 WHAT THE TAPE DRIVE RETURNS
Bit
Byte
32
7
6
5
4
3
2
1
0
(MSB)
…
Cartridge Serial Number
(LSB)
43
44
Reserved
EXPCLN
SrvRqDr
45
Reserved
MedDgrd MedDead
Drive Temperature
46
Byte 00, Bit 7 – Valid
This field indicates whether the sense data in the Information field (bytes 03
through 06) is valid (conforms to the SCSI-2 standard), as follows:
0
The data in the Information field is undefined
1
The data in the Information field is valid for the command
receiving the Check Condition status
Byte 00, Bits 6 through 0 – Error Code
This field indicates with what command the reported sense data is associated,
as follows:
70h
The sense data is associated with the command that
received the Check Condition status
71h
The sense data is for a deferred error condition and is
associated with an earlier command
Byte 02, Bit 7 – FMK (Filemark)
This bit indicates whether the current command detected a filemark or
setmark, as follows:
0
No filemarks or setmarks were detected
1
The current command detected a filemark or setmark
Byte 02, Bit 6 – EOM (End of Medium)
When set to 1, this bit indicates that one of the following end of medium
conditions has been encountered.
The tape is at or past the early warning (logical end of partition or tape).
The tape is at LBOP (the tape drive encountered the logical beginning of
partition during a backward motion).
OCTOBER 2008
VXA-2 TAPE DRIVE
18-3
CHAPTER 18 REQUEST SENSE (03h)
Byte 02, Bit 5 – ILI (Illegal Length Indicator)
When set to 1, this bit indicates that the logical block length requested did not
match the actual logical block length of the data recorded on the tape.
Byte 02, Bits 3 through 0 – Sense Key
This field contains the sense key associated with the current sense data.
Table 18-1 lists the sense key values supported by the tape drive. See
Appendix A for the ASC, ASCQ, and FSC values associated with each sense
key.
Table 18-1 Sense Key values
Sense Key
Meaning
Explanation
0h
No Sense
Indicates that there is no specific sense key information to be reported for the
designated logical unit. This occurs when a command completes successfully
or returns Check Condition or Command Terminated status with the FMK,
EOM, or ILI bits set to 1.
1h
Recovered
Error
Indicates that the last command completed successfully with some recovery
action performed by the tape drive. Details may be available by examining the
additional sense bytes and the information field.
2h
Not Ready
Indicates that the tape drive does not contain a data cartridge or that the data
cartridge is not loaded. Operator intervention may be required to correct this
condition.
3h
Medium
Error
Indicates that the command terminated with a non-recoverable error
condition that may have been caused by a flaw in the tape or an error in the
recorded data. The tape drive may also return this sense key if it is unable to
distinguish between a flaw in the tape and a specific hardware failure (sense
key 4h).
4h
Hardware
Error
Indicates that the tape drive detected a non-recoverable hardware failure (for
example a device failure or parity error) while performing the command or
during a self-test.
5h
Illegal
Request
Indicates that there was an illegal parameter in the CDB or in the additional
parameters supplied as data for a command or that the tape drive is in the
wrong mode to execute the command. If the tape drive detects an invalid
parameter in the CDB, the tape is not written. If the tape drive detects an
invalid parameter in the additional parameters supplied as data, the tape may
already be altered. This sense key can also indicate an invalid Identify
message.
18-4
SCSI REFERENCE
1009566-001
18.3 WHAT THE TAPE DRIVE RETURNS
Table 18-1 Sense Key values (continued)
Sense Key
Meaning
Explanation
6h
Unit
Attention
Indicates one of the following:
ƒ The tape drive has been reset (by a power-on reset, a Bus Device Reset
message, or a SCSI bus reset).
ƒ An initiator changed the MODE SELECT parameters since the last command
was issued to the tape drive.
ƒ The eject button was pressed and the data cartridge was ejected.
ƒ A data cartridge was inserted and automatically loaded.
ƒ The internal microcode (firmware) was changed.
ƒ A log parameter (counter) reached a specified threshold value (assuming that
RLEC bit on the MODE SELECT Control Mode page is set to 1).
This sense key is reported the first time any command is issued by each
initiator after the condition is detected, and the requested command is not
performed. This sense key is cleared when the next command other than
INQUIRY or REQUEST SENSE is received by the tape drive.
7h
Data
Protect
Indicates that a command that writes to tape was attempted on a
write-protected data cartridge. The write operation is not performed.
8h
Blank
Check
Indicates that the tape drive encountered blank tape or format-defined EOD
(blank tape) during a read, space, or locate operation.
Bh
Aborted
Command
Indicates that the tape drive aborted the command. This condition occurs
when an Initiator Detected Error (05h) message is received during command
execution or when a Message Reject (07h) or SCSI bus parity error is detected
by the tape drive during Command or Data Out phase.
The initiator may be able to recover by trying the command again.
Dh
Volume
Overflow
Indicates that the last WRITE or WRITE FILEMARKS command reached the
physical end of tape (PEOT) and that data may remain in the buffer.
Eh
Miscompare Indicates that the source data did not match the data read from the tape.
Bytes 03 through 06 – Information
The value in this field is command and error condition dependent. In general,
it represents the number of blocks or bytes of data that were not processed due
to the condition that resulted in a Check Condition status.
For the READ, READ BUFFER, WRITE, WRITE BUFFER, WRITE
FILEMARKS, and VERIFY commands, this field contains the difference
between the number of blocks or bytes requested and the number that were
actually transferred.
For the SPACE command, this field contains the difference between the
number of filemarks, setmarks, or data blocks requested and the actual
number spaced over. By default, when a backward space operation is
requested, the difference is a negative number using 2’s complement format
(see page 9-25 for information about changing the way tape drive reports
residual values during a backward space operation).
OCTOBER 2008
VXA-2 TAPE DRIVE
18-5
CHAPTER 18 REQUEST SENSE (03h)
This field is valid only when the Valid bit (byte 00, bit 7) is set to 1. When the
Valid bit is set to 0, any data in this field is invalid.
Byte 07 – Additional Sense Length
This byte indicates the length, in bytes, of any additional sense data provided
by the tape drive, excluding this byte. The tape drive returns 40 (28h) bytes of
additional sense data.
Bytes 08 through 11 – Command-Specific Information
The tape drive does not use this field. The value returned is always 0.
Byte 12 – Additional Sense Code (ASC)
This field contains the Additional Sense Code (ASC) data. The ASC, in
conjunction with the Additional Sense Code Qualifier (byte 13), provides
additional information about the error indicated by the sense key. Table A-1 on
page A-2 provides detailed information about the valid combinations of ASC
and ASCQ and their meanings. Where applicable, the “Exceptions and Error
Conditions” section at the end of each command chapter provides detailed,
command-specific information.
Byte 13 – Additional Sense Code Qualifier (ASCQ)
This field contains the Additional Sense Code Qualifier (ASCQ) data. The
ASCQ, in conjunction with the Additional Sense Code (byte 12), provides
additional information about the error indicated by the sense key. Table A-1 on
page A-2 provides detailed information about the valid combinations of ASC
and ASCQ and their meanings. Where applicable, the “Exceptions and Error
Conditions” section at the end of each command chapter provides detailed,
command-specific information.
Byte 14 – Field Replacable Unit Code
There are no field replaceable parts. The value returned for this field is
always 0.
Bytes 15 through 17 – Sense Key Specific Data for Illegal Request (SK 5h)
When the sense key indicates Illegal Request (5h) and the SKSV is 1, the Sense
Key Specific Data returns additional information about the Illegal Request,
formatted as follows:
Bit
Byte
15
16
7
6
SKSV
C/D
4
Reserved
3
BPV
2
1
0
Bit Pointer
(MSB)
Field Pointer
17
18-6
5
SCSI REFERENCE
(LSB)
1009566-001
18.3 WHAT THE TAPE DRIVE RETURNS
Byte 15, Bit 7 – SKSV (Sense Key Specific Valid) This field indicates whether
the data in the Sense Key Specific Data field (bytes 15 through 17) is valid, as
follows:
0
The Sense Key Specific Data is not valid
1
The Sense Key Specific Data is valid. The Sense Key
Specific Data is valid only when the sense key is Illegal
Request (5h)
Byte 15, Bit 6 – C/D (Command/Data) This field indicates the location of the
illegal parameter, as follows:
0
The illegal parameter is in the parameters sent by the
initiator
1
The illegal parameter is in the command descriptor block
Byte 15, Bit 3 – BPV (Bit Pointer Valid) This field indicates whether the bit
pointer for the illegal parameter is valid, as follows:
0
The Bit Pointer information is not valid
1
The Bit Pointer information is valid
Byte 15, Bits 2 through 0 – Bit Pointer This field indicates which bit of the
byte indicated by the Field Pointer is in error. If a multiple bit field is in error,
the Bit Pointer indicates the most significant (left-most) bit of the field. Refer to
the appropriate command chapter in this reference for the definition of the
indicated bit.
Bytes 16 and 17 – Field Pointer This field indicates which byte of the
command descriptor block or parameter data was in error. If a multiple-byte
field is in error, the Field Pointer indicates the most significant (left-most) byte
of the field. Refer to the appropriate command chapter in this reference for the
definition of the indicated byte.
Byte 18 – Fault Symptom Code (FSC)
The Fault Symptom Code is an Tandberg Data-unique value used to provide
specific information about the condition that resulted in the Check Condition
status. Table A-1 on page A-2 shows the FSC values associated with each
ASC/ASCQ combination.
OCTOBER 2008
VXA-2 TAPE DRIVE
18-7
CHAPTER 18 REQUEST SENSE (03h)
Bytes 19 through 21 – Unit Sense
The Unit Sense field provides additional status data for the tape drive,
formatted as follows:
Bit
Byte
7
6
5
4
3
2
Reserved
19
1
0
TNP
LBOT
Reserved
20
Reserved
21
CLN
PEOT
Reserved
For each status bit defined in the Unit Sense field, a value of 0 represents a
normal or Good status. When a status bit is set to 1, the condition indicated by
that bit exists.
Note: All Reserved bits have an effective value of 0.
Byte 19, Bit 1 – TNP (Tape Not Present) The tape drive does not have a data
cartridge inserted.
Byte 19, Bit 0 – LBOT (Logical Beginning of Tape)
positioned at the logical beginning of tape.
The data cartridge is
Byte 21, Bit 3 – CLN (Clean) The tape drive needs to be cleaned. This bit is
reset to 0 when a successful cleaning cycle is performed. The tape drive’s
cleaning requirements depend on the number of tape motion hours and the
type of tape being used.
Byte 21, Bit 2 – PEOT (Physical End of Tape)
at PEOT.
The data cartridge is positioned
Byte 22 – Command
The value in this field indicates the operation code of the SCSI command for
which the current sense data was issued.
Bytes 23 through 25 – Remaining Tape
This field indicates the amount of tape remaining, in 16-KB physical units. This
value equals the logical end of tape (LEOT) position minus the current
physical position. For a partitioned tape, this value equals the number of
16-KB units between the current physical location and logical end of partition
(LEOP). If the current position is beyond LEOT or if there is no data cartridge
loaded, the value is 0.
Byte 26 – FSC N-1
This field contains the non-zero Fault Symptom Code that immediately
preceded the current one.
18-8
SCSI REFERENCE
1009566-001
18.3 WHAT THE TAPE DRIVE RETURNS
Byte 27 – Command N-1
This field contains the operation code of the command for which the FSC N-1
was generated.
Byte 28 – FSC N-2
This field contains the non-zero Fault Symptom Code that immediately
preceded FSC N-1.
Byte 29 – Command N-2
This field contains the operation code of the command for which the FSC N-2
was generated.
Byte 30 – FSC N-3
This field contains the non-zero Fault Symptom Code that immediately
preceded FSC N-2.
Byte 31 – Command N-3
This field contains the operation code of the command for which the FSC N-3
was generated.
Byte 32 through 43 – Cartridge Serial Number
This field contains the serial number of the cartridge currently inserted in the
tape drive.
Byte 44, Bit 0 – SrvRqDr (Service Required for Drive)
This bit is set to 1 if the drive requires service.
Byte 44, Bit 1 – EXPCLN (Expired Cleaning Cartridge)
This bit is set to 1 if the drive detects that an expired cleaning cartridge was
inserted. The EXPCLN bit setting is maintained across a power cycle or drive
reset, and resets to 0 only after a successful cleaning cycle is performed.
Byte 45, Bit 1 – MedDgrd (Media is Degraded)
This bit is set to 1 if the media is marginal.
Byte 45, Bit 0 – MedDead (Media is Dead)
This bit is set to 1 if the media is unusable.
Byte 46 – DRVTEMP (Drive Temperature)
This byte returns the current drive temperature as a hex value in degrees
centigrade. For example, a drive temperature of 43C returns as 0x2B.
OCTOBER 2008
VXA-2 TAPE DRIVE
18-9
CHAPTER 18 REQUEST SENSE (03h)
18.4 SENSE BYTE PENDING STATUS
When the tape drive reports Check Condition status in response to a
command from an initiator, the tape drive retains the sense byte pending
status, including error information and Check Condition status, for the
initiator until one of the following occurs:
Error information is reset by the next command other than INQUIRY from
the same initiator.
Error information is reset by a power-on reset, a Bus Device Reset message,
or a SCSI bus reset condition.
18-10
SCSI REFERENCE
1009566-001
19
RESERVE UNIT (16h)
Bit
Byte
7
6
5
4
3
2
1
0
00
0
0
0
1
0
1
1
0
01
Logical Unit No
3rdPty
Third Party Device ID
RSVD
02
Reserved
03
04
Control
05
19.1 ABOUT THIS COMMAND
The RESERVE UNIT command reserves the tape drive for an initiator’s
exclusive use or, if third-party reservations are in effect, for another SCSI
device’s use. The reservation remains in effect until a RELEASE UNIT
command is received from the same initiator or until the tape drive is reset by
a SCSI bus reset, a Bus Device Reset message, or a power-on reset.
It is not an error for the initiator that made the last reservation to send another
valid RESERVE UNIT command.
19.2 CDB FIELD DEFINITIONS
Logical Unit Number (LUN) – Byte 01, Bits 7 through 5
The tape drive only supports LUN 0. The value for this field must be 0.
Byte 01, Bit 4 – 3rdPty
This bit indicates whether a third-party reservation is requested, as follows:
OCTOBER 2008
0
A third-party reservation is not requested
1
A third-party reservation is requested
VXA-2 TAPE DRIVE
19-1
CHAPTER 19 RESERVE UNIT (16h)
Byte 01, Bits 3 through 1 – Third Party Device ID
This field indicates the SCSI ID of the device for which the initiator is making
the third-party reservation. The tape drive ignores this field if the initiator is
not requesting a third-party reservation.
19.3 EXCEPTIONS AND ERROR CONDITIONS
If the tape drive is reserved and it receives any command (other than an
INQUIRY (12h), PREVENT/ALLOW MEDIUM REMOVAL (1Eh), or REQUEST
SENSE (03h) command) from another initiator, it does not honor the
command. Instead, it returns Reservation Conflict (18h) status to the initiator
that sent the command.
19-2
SCSI REFERENCE
1009566-001
20
REWIND (01h)
Bit
Byte
7
6
5
4
3
2
1
0
00
0
0
0
0
0
0
0
1
01
Logical Unit Number
Reserved
Immed
02
Reserved
03
04
Control
05
20.1 ABOUT THIS COMMAND
The REWIND command causes the tape drive to rewind the tape to the logical
beginning of tape (LBOT) or, if the tape is partitioned, to the logical beginning
of the partition (LBOP) in which the tape is currently positioned.
Notes:
If the disconnect option is enabled, the tape drive disconnects from the initiator
while the REWIND command is executing.
If the tape is already at LBOT (or LBOP for a partitioned tape) and there is no
data in the buffer, no tape motion results.
If the tape drive receives a command while the tape is rewinding, its response is
determined by the value in the RespDuringImmed field on the MODE SELECT
Vendor Unique Parameters Page 1 page (see page 9-24).
If the REWIND command follows a WRITE (0Ah) or WRITE FILEMARKS (10h)
command, the tape drive writes all buffered data, filemarks, or setmarks and
appends an end of data (EOD) mark before the tape is rewound.
If an error occurs during the writing of the data in the buffer to the tape, the tape
drive returns Check Condition status. The rewind operation is not performed.
The initiator should issue a REQUEST SENSE (03h) command to determine the
cause of the error.
OCTOBER 2008
VXA-2 TAPE DRIVE
20-1
CHAPTER 20 REWIND (01h)
If there is data in the buffer because an earlier WRITE (0Ah) command was
terminated with Check Condition status, the tape drive discards that data before
rewinding the tape.
20.2 CDB FIELD DEFINITIONS
Logical Unit Number (LUN) – Byte 01, Bits 7 through 5
The tape drive only supports LUN 0. The value for this field must be 0.
Byte 01, Bit 0 – Immed
The value in this field determines when command status is returned to the
initiator, as follows:
0
Status is reported when the REWIND command is
completed
1
Status is reported when the REWIND command is initiated
by the tape drive
If the tape drive’s buffer contains data from a previous WRITE command, the
tape drive disconnects from the initiator (if disconnect is enabled) and writes
the data in the buffer to the tape.
If the Immed bit is set to 1, the tape drive reconnects to the initiator when
the write operation has completed successfully. It then returns Good status
and performs the rewind operation.
Note:
Completing the write operation includes emptying the buffer to tape
and writing the EOD mark.
If the Immed bit is set to 0, the tape drive reconnects and returns status
when the rewind operation is complete.
20.3 EXCEPTIONS AND ERROR CONDITIONS
Table 20-1 lists exceptions and error conditions that cause the tape drive to
return Check Condition status for the REWIND command.
Table 20-1 REQUEST SENSE data for REWIND command errors and exceptions
Sense
Key
ASC
ASCQ
(Byte 12) (Byte 13)
Explanation
02h
04h
01h
Not Ready. Tape drive is not ready, it is in process of initializing itself.
02h
04h
03h
Not Ready. The tape drive is not ready because it needs manual
intervention.
02h
3Ah
00h
Not Ready. Tape drive is not ready. Command requires a tape, and no
tape is present.
20-2
SCSI REFERENCE
1009566-001
20.3 EXCEPTIONS AND ERROR CONDITIONS
Table 20-1 REQUEST SENSE data for REWIND command errors and exceptions (continued)
Sense
Key
ASC
ASCQ
(Byte 12) (Byte 13)
Explanation
03h
30h
02h
Medium Error. The tape format is incompatible with the tape drive
hardware or microcode.
03h
31h
01h
Medium Error. The tape format is corrupted.
04h
15h
01h
Hardware Error. The tape drive cannot position the tape correctly.
06h
30h
00h
Unit Attention. Incompatible media was rejected after the cartridge
was inserted.
OCTOBER 2008
VXA-2 TAPE DRIVE
20-3
CHAPTER 20 REWIND (01h)
Notes
20-4
SCSI REFERENCE
1009566-001
21
SEND DIAGNOSTIC (1Dh)
Bit
Byte
7
6
5
4
3
2
1
0
00
0
0
0
1
1
1
0
1
PF
RSVD
SelfTest
DevOffL
UnitOffL
Logical Unit Number
01
Reserved
02
03
(MSB)
Parameter List Length
04
(LSB)
Control
05
21.1 ABOUT THIS COMMAND
The SEND DIAGNOSTIC command causes the tape drive to perform its
diagnostic self-test. If a test is successful, the tape drive returns Good status;
otherwise, it returns Check Condition status. When this command is followed
by a RECEIVE DIAGNOSTIC RESULTS (1Ch) command or a REQUEST
SENSE (03h) command, the results of the self-test are reported to the initiator.
Notes:
To ensure that the diagnostic data returned is valid, the SEND DIAGNOSTIC
command must be immediately followed by the RECEIVE DIAGNOSTIC
RESULTS command.
To ensure that the results of the diagnostic test are not destroyed by a command
sent by another initiator, the tape drive should be reserved for the initiator’s
exclusive use.
The initiator must support the disconnect option if you plan to use the SEND
DIAGNOSTIC command because the tape drive will disconnect from the
initiator while the command is executing.
OCTOBER 2008
VXA-2 TAPE DRIVE
21-1
CHAPTER 21 SEND DIAGNOSTIC (1Dh)
21.2 CDB FIELD DEFINITIONS
Logical Unit Number (LUN) – Byte 01, Bits 7 through 5
The tape drive only supports LUN 0. The value for this field must be 0.
Byte 01, Bit 4 – PF (Page Format)
This field specifies whether the format of the parameter list for the SEND
DIAGNOSTIC command conforms to the page format defined in the SCSI-2
standard, as follows:
0
The parameter list uses non-page format
This value is only valid if the SelfTest bit (byte 01, bit 2) is
set.
1
The parameter list uses the SCSI page format
This value is valid for all pages.
Byte 01, Bit 2 – SelfTest
This bit specifies whether the tape drive should perform its default diagnostic
self-test, as follows:
0
Perform the diagnostic tests specified in the Parameter List
1
Preform the default diagnostic self-test
The Parameter List Length must be 0.
Byte 01, Bit 1 – DevOffL
This bit specifies whether the tape drive is allowed to perform diagnostic tests
whose results may be detected by subsequent I/O processes (for example unit
reservations, log parameters, or sense data), as follows:
0
The tape drive may not perform diagnostic tests whose
results may be detected by subsequent I/O processes.
1
The tape drive may perform diagnostic tests whose results
may be detected by subsequent I/O processes.
Byte 01, Bit 0 – UnitOffL
This field specifies whether the tape drive is allowed to perform diagnostic
tests that might affect the tape, such as writing data or repositioning the tape,
as follows:
21-2
SCSI REFERENCE
0
The tape drive may not perform diagnostic test that might
affect the tape.
1
The tape drive may perform diagnostic test that affect the
tape.
1009566-001
21.3 ADDITIONAL DIAGNOSTIC DATA
Bytes 03 and 04 – Parameter List Length
The value for this field specifies the number of bytes of data that follow in the
parameter list. The additional data is one of the diagnostic pages described in
the following sections. Table 21-1 lists the diagnostic pages supported by the
tape drive and the maximum page length of each.
Table 21-1 Maximum page length of each supported SEND DIAGNOSTIC page
Page Lengtha
Page Code Page Name
a
00h
Supported Diagnostic Pages page
0000h (0 bytes)
F0h
Self Test page
0000h (0 bytes)
Maximum page length does not include the four-byte Diagnostic Parameter Header, which must be
included with each page.
21.3 ADDITIONAL DIAGNOSTIC DATA
Following each SEND DIAGNOSTIC CDB is a parameter list for the Diagnostic
page you are sending. The parameter list for each diagnostic page begins with
a four-byte Diagnostic Parameter Header (bytes 00 through 03), followed by
the parameters for that page. The Diagnostic Parameter Header indicates the
page code for the diagnostic page and indicates the total length of the
parameter list to follow.
Bit
Byte
7
6
5
4
3
00
Page Code
01
Reserved
02
(MSB)
2
1
Page Length
03
0
(LSB)
Byte 00 – Page Code
This field identifies the page code of the diagnostic page being sent. Table 21-1
lists the page codes for all of the supported diagnostic pages.
Bytes 02 and 03 – Page Length
This field indicates the total number of bytes that will follow this byte. The
valid value for this field depends on the value in the Page Code field.
Table 21-1 lists of the page length for each of the supported diagnostic pages.
OCTOBER 2008
VXA-2 TAPE DRIVE
21-3
CHAPTER 21 SEND DIAGNOSTIC (1Dh)
21.3.1
SUPPORTED DIAGNOSTIC PAGES PAGE (PAGE CODE 00h)
When the value of the Page Code field (byte 00) in the Diagnostic Parameter
Header is 00h, the data that follows contains parameters for the Supported
Diagnostic Pages page. This page allows the initiator to retrieve the list of
supported pages using the RECEIVE DIAGNOSTIC RESULTS command. The
value in the Page Length field (bytes 2 and 3) of the Diagnostic Parameter
Header for this page is 0000h, indicating that there are no parameters
associated with this diagnostic page.
Bit
Byte
7
6
5
4
3
00
Page Code (00h)
01
Reserved
02
(MSB)
2
1
Page Length (0000h)
03
21.3.2
0
(LSB)
SELF TEST PAGE (PAGE CODE F0h)
When the value of the Page Code field (byte 00) in the Diagnostic Parameter
Header is F0h, the Self Test page is executed by the SEND DIAGNOSTIC
command. The value in the Page Length field (bytes 2 and 3) of the Diagnostic
Parameter Header is 0000h, indicating that there are no parameters associated
with this diagnostic page. This diagnostic page has the same effect as setting
the SelfTest bit (byte 1, bit 2) in the CDB.
Bit
Byte
7
6
5
4
3
00
Page Code (95h)
01
Reserved
02
(MSB)
03
21-4
SCSI REFERENCE
Page Length (0000h)
2
1
0
(LSB)
1009566-001
22
SPACE (11h)
Bit
Byte
7
6
5
4
3
2
1
0
00
0
0
0
1
0
0
0
1
Logical Unit Number
01
02
Reserved
Code
(MSB)
Count
03
(LSB)
04
Control
05
22.1 ABOUT THIS COMMAND
The SPACE command enables the tape drive to perform forward or backward
searches. You can use this command to space directly to the end of data (EOD)
or to space over a specified number of logical blocks, filemarks, or setmarks.
Notes:
The tape drive can space over both fixed- and variable-length logical blocks; it
determines the type of spacing to use according to the type of block found on
the tape.
If the disconnect option is enabled, the tape drive can disconnect from the
initiator while the SPACE command is executing.
If you attempt to space backward immediately after writing data, filemarks, or
setmarks, the tape drive will complete the write operation before performing the
space operation. Completing the write operation includes writing any buffered
data to tape and writing an end of data (EOD) mark.
If an error occurs when the data in the buffer is being written, the tape drive
returns Check Condition status and the space operation is not performed. You
can issue a REQUEST SENSE (03h) command to determine the cause of the
error.
OCTOBER 2008
VXA-2 TAPE DRIVE
22-1
CHAPTER 22 SPACE (11h)
On a partitioned tape, spacing is limited to locations within the current partition.
If you want to space to a location outside of the current partition, you must move
to the new partition using the LOCATE or MODE SELECT command.
22.2 CDB FIELD DEFINITIONS
Logical Unit Number (LUN) – Byte 01, Bits 7 through 5
The tape drive only supports LUN 0. The value for this field must be 0.
Byte 01, Bits 2 through 0 – Code
The Code field specifies the type of space operation the tape drive is to
perform. Table 22-1 lists the valid values for the Code field and indicates the
type of operation each specifies. See page 22-3 for information about the errors
and exceptions that can occur for each of these values.
Table 22-1 Valid values for the Code field in the SPACE (11h) CDB
Value of Type of operation
Code field
000b
Space over n fixed or
variable-length blocks
Space over the next n blocks. If the tape drive encounters a
filemark, or if it encounters a setmark and the RSmk bit in MODE
SELECT is set to 1, the tape drive terminates the command.
Space over n filemarks
Space over the next n filemarks. If the tape drive encounters a
setmark and the RSmk bit on the MODE SELECT Device
Configuration page (Page Code=10h) is set to 1, the tape drive
terminates the command.
Space to end of data
When you set the Code field to 011b, the tape drive ignores the
setting of the Count field. Instead, it spaces forward until it
encounters EOD. The tape is positioned so that a subsequent
WRITE command can append data after the last block, filemark,
or setmark written before the end of data.
Space over n setmarks
When you set the Code field to 100b, the tape drive ignores the
setting of the RSmk bit on the MODE SELECT Device
Configuration page (Page Code=10h). In addition, the tape drive
ignores filemarks.
Reserved
If you set the Code field to one of these values, the tape drive
returns Check Condition status with the sense key set to Illegal
Request (5h).
001b
011b
100b
010b
Notes
101b
110b
111b
Bytes 02 through 04 – Count
The count value, n, in this field represents the number of blocks, filemarks, or
setmarks to be spaced over. The value of n determines the direction of spacing,
as follows:
22-2
SCSI REFERENCE
1009566-001
22.3 EXCEPTIONS AND ERROR CONDITIONS
A positive value of n in the Count field causes the tape drive to space
forward n blocks, filemarks, or setmarks. When the space operation is
complete, the tape is logically positioned on the EOD side of the nth block,
filemark, or setmark.
A negative value of n (in 2’s complement notation) in the Count field causes
the tape drive to space backward over n blocks, filemarks, or setmarks.
When the operation is complete, the tape is logically positioned on the BOP
side of the nth block, filemark, or setmark.
A value of 0 in the Count field causes no change in the tape position and is
not an error.
Note: The tape drive ignores the Count field when spacing to end of data.
22.3 EXCEPTIONS AND ERROR CONDITIONS
The following exceptions and error conditions can occur with the SPACE
command.
Filemark Detected
If the Code field has a value of 000b (space over n logical blocks) and a filemark
is detected, the tape drive terminates the command and returns Check
Condition status. The REQUEST SENSE data is set as follows:
Valid
1
Filemark
1
Sense Key
0h (No Sense)
Information
bytes
Indicate the difference between the requested number of
blocks and the actual number of blocks spaced over. This
value is always positive.
ASC
00h
ASCQ
01h (Filemark Detected)
FSC
28h
If the filemark was detected during a forward search, the tape is logically
positioned on the EOD side of the filemark. If the filemark was detected
during a backward search, the tape is logically positioned on the BOP side of
the filemark.
Note: Filemarks are ignored if you previously set the Code field to space over
setmarks (100b).
OCTOBER 2008
VXA-2 TAPE DRIVE
22-3
CHAPTER 22 SPACE (11h)
Early Warning Encountered
If an early warning is encountered after the completion of a space operation
(regardless of the value of the Code field) and the REW bit on the MODE
SELECT Device Configuration page (Page Code 10h) is set to 1, the tape drive
terminates the command and returns Check Condition status. The REQUEST
SENSE data is set as follows:
Valid
0 or 1
EOM
1
Sense Key
3h (Medium Error)
Information
bytes
The Information bytes are invalid.
ASC
00h
ASCQ
02h (End of Tape or End of Partition Detected)
FSC
2Ah, 2Dh
If the early warning was detected during a forward search, the tape is logically
positioned on the EOD side of the target filemark, setmark, or logical block. If
the early warning was detected during a backward search, the tape is logically
positioned on the BOP side of the target filemark, setmark, or logical block.
Setmark Detected
If the Code field has a value of 000b (space over n logical blocks) or 001b (space
over n filemarks) and a setmark is detected, the tape drive looks at the setting
of the RSmk bit on the MODE SELECT Device Configuration page (Page
Code 10h):
If the bit is 0 (do not report setmarks), the tape drive continues to space over
blocks or filemarks.
If the bit is 1 (report setmarks), the tape drive terminates the command and
returns Check Condition status. The REQUEST SENSE data is set as follows:
22-4
SCSI REFERENCE
Valid
1
Filemark
1
Sense Key
0h (No Sense)
Information
bytes
Indicate the difference between the requested number of
blocks or filemarks and the actual number of blocks or
filemarks spaced over. This value is always positive.
ASC
00h
ASCQ
03h (Setmark Detected)
FSC
40h
1009566-001
22.3 EXCEPTIONS AND ERROR CONDITIONS
If the setmark was detected during a forward search, the tape is logically
positioned on the EOD side of the setmark. If the setmark was detected during
a backward search, the tape is logically positioned on the BOP side of the
setmark.
PBOT or PBOP Encountered
If the Code field has a value of 000b, 001b, or 100b (space over logical blocks,
filemarks, or setmarks) and the physical beginning of tape (PBOT) or physical
beginning of partition (PBOP) is encountered while spacing backward, the
tape drive terminates the command and returns Check Condition status. The
REQUEST SENSE data is set as follows:
Valid
1
EOM
1
Sense Key
0h (No Sense)
Information
bytes
Indicate the difference between the requested number of
blocks, filemarks, or setmarks and the actual number
spaced over. This value is always positive.
ASC
00h
ASCQ
04h (Beginning of Tape or Beginning of Partition Detected)
FSC
29h, 2Bh
After PBOT (or PBOP) is encountered, the tape is positioned at LBOT (or
LBOP).
EOD Detected
If the Code field has a value of 000b (space over n logical blocks), 001b (space
over n filemarks), or 100b (space over n setmarks), and the EOD mark is
detected, the tape drive returns Check Condition status. The REQUEST
SENSE data is set as follows:
Valid
1
EOM
0 or 1. Set to 1 if early warning has been detected.
Sense Key
Blank Check (8h)
Information
bytes
Indicate the difference between the requested number of
blocks, filemarks, or setmarks and the actual number
spaced over. This value is always positive.
ASC
00h
ASCQ
05h (EOD Detected)
FSC
2Ch
The tape is positioned so that a subsequent WRITE command can append data
after the last information written before EOD.
OCTOBER 2008
VXA-2 TAPE DRIVE
22-5
CHAPTER 22 SPACE (11h)
Unrecoverable Error
If an unrecoverable media or hardware error occurs during the space
operation, the tape drive terminates the SPACE command and returns Check
Condition status. The REQUEST SENSE data is set as follows:
Valid
0 or 1
Sense Key
Medium Error (3h) or Hardware Error (4h)
Information
bytes
If Valid=1, indicate the difference between the requested
number of blocks, filemarks, or setmarks and the actual
number spaced over. The actual length does not include
the unrecovered block. This value is always positive.
Other bits and Depend on the error condition
bytes
When the SPACE command is terminated, the position of the tape drive
depends on whether a forward or backward space was attempted:
If the error occurred during a forward space, the tape drive is positioned
after the unrecovered block.
If the error occurred during a backward space, the tape drive is positioned
before the unrecovered block.
Table 22-2 lists additional exceptions and error conditions that cause the tape
drive to return Check Condition status for the SPACE command.
Table 22-2 REQUEST SENSE data for SPACE command errors and exceptions
Sense
Key
ASC
ASCQ Description
(Byte 12) (Byte 13)
02h
04h
01h
Not Ready. In the process of becoming ready. The tape drive is in the
process of initializing itself.
02h
04h
03h
Not Ready. The tape drive requires manual intervention.
02h
3Ah
00h
Not Ready. The command requires a tape and no tape is present.
03h
00h
02h
Medium Error. The tape drive encountered the physical end of tape
(PEOT) or the physical end of partition (PEOP) before completing the
operation.
03h
14h
00h
Medium Error. The tape drive cannot perform the locate operation
because it cannot read data from the tape.
03h
14h
03h
Medium Error. The tape drive cannot locate the end of data (EOD) on
the tape.
0h
31h
00h
Medium Error. The format of the currently loaded tape is corrupted.
22-6
SCSI REFERENCE
1009566-001
22.3 EXCEPTIONS AND ERROR CONDITIONS
Table 22-2 REQUEST SENSE data for SPACE command errors and exceptions (continued)
Sense
Key
ASC
ASCQ Description
(Byte 12) (Byte 13)
4h
15h
01h
Hardware Error. The tape drive cannot properly position the media.
6h
30h
00h
Unit Attention. The currently loaded tape is incompatible with the
tape drive.
OCTOBER 2008
VXA-2 TAPE DRIVE
22-7
CHAPTER 22 SPACE (11h)
Notes
22-8
SCSI REFERENCE
1009566-001
23
TEST UNIT READY (00h)
Bit
Byte
00
01
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
0
Logical Unit Number
Reserved
02
Reserved
03
04
Control
05
23.1 ABOUT THIS COMMAND
The TEST UNIT READY command provides a means for determining if the
tape drive is ready to accept an appropriate medium access command.
The TEST UNIT READY command returns Good status after the tape is loaded
if the tape drive is ready to accept a medium access command without
returning Check Condition status. If the tape drive is not ready to accept a
medium access command, the tape drive returns Check Condition status with
the sense key set to Not Ready (2h).
Note: The TEST UNIT READY command is not a request for a unit self-test.
23.2 CDB FIELD DEFINITIONS
Logical Unit Number (LUN) – Byte 01, Bits 7 through 5
The tape drive only supports LUN 0. The value for this field must be 0.
OCTOBER 2008
VXA-2 TAPE DRIVE
23-1
CHAPTER 23 TEST UNIT READY (00h)
23.3 EXCEPTIONS AND ERROR CONDITIONS
Table 23-1 lists exceptions and error conditions that cause the tape drive to
return Check Condition status for the INQUIRY command.
Table 23-1 REQUEST SENSE data for TEST UNIT READY command errors and exceptions
Sense
Key
ASC
ASCQ Description
(Byte 12) (Byte 13)
02h
04h
01h
Not Ready. The tape drive is in the process of initializing itself.
02h
04h
03h
Not Ready. The tape drive requires manual intervention.
02h
3Ah
00h
Not Ready. The command requires a tape and no tape is present.
05h
25h
00h
Illegal Request. The logical unit specified in the CDB is not supported.
23-2
SCSI REFERENCE
1009566-001
24
WRITE (0Ah)
Bit
Byte
00
7
6
5
4
3
2
1
0
0
0
0
0
1
0
1
0
Logical Unit Number
01
02
Reserved
Fixed
(MSB)
Transfer Length
03
(LSB)
04
Control
05
24.1 ABOUT THIS COMMAND
The WRITE command transfers one or more bytes or blocks of data from the
initiator to the media loaded in the tape drive. The VXA-2 tape drive writes
data to the tape in either VXA-1 or VXA-2 format. The data is compressed or
uncompressed according to the setting of the DCE (data compression enable)
bit in the MODE SELECT command (see page 9-11).
After writing data, the tape drive writes an end of data (EOD) mark to indicate
the location of the last data on tape. The EOD mark is overwritten when
additional data is appended to the last data on the tape.
24.1.1
TAPE POSITIONING
This section describes the legal tape positions for a write operation.
Tape Positioned at LBOT or LBOP
When writing to a tape positioned at LBOT or LBOP, the tape drive
automatically writes a new LBOT (or LBOP) pattern and then writes the data
from the buffer.
OCTOBER 2008
VXA-2 TAPE DRIVE
24-1
CHAPTER 24 WRITE (0Ah)
Appending Data
When writing to tape, the tape drive can append new data to existing data at
certain locations only. If the tape is not positioned at a legal location, the tape
drive returns Check Condition status with the sense key set to Illegal Request
(5h). The legal locations for appending data are:
EOD mark (the EOD mark is overwritten as new data is appended)
Beginning or end of a filemark
Beginning or end of a setmark
Note: If data is appended at the beginning of a filemark or setmark, the filemark
or setmark is overwritten.
24.1.2
DATA BUFFERING
The tape drive provides two modes of operation for the WRITE command:
unbuffered and buffered. The mode of operation is set with the MODE
SELECT command (byte 02, bits 6 through 4, in the Parameter List Header).
Unbuffered Write Operation
When the tape drive is set for an unbuffered write operation, it returns Good
status as soon as all data blocks are written to tape.
Buffered Write Operation
When the tape drive is set for a buffered write operation, it returns Good
status as soon as all data blocks are successfully transferred to the buffer. The
data in the buffer is written to tape when one of the following conditions
occurs:
The Buffer Full Threshold is reached during a WRITE command (see
Section 2.4 on page 2-4).
The tape drive receives one of the following commands:
ERASE
LOCATE
LOAD/UNLOAD
READ
READ BUFFER
REWIND
SPACE
WRITE BUFFER
WRITE FILEMARKS (with the Immed bit set to 0)
The operator presses the eject button.
The time specified for the Write Delay Time field in the Device
Configuration Page elapses (note, however, if the Write Delay Time field is 0,
a partially full buffer is not flushed to tape). See page 9-14 for more
information about the Write Delay Time field.
24-2
SCSI REFERENCE
1009566-001
24.2 CDB FIELD DEFINITIONS
24.2 CDB FIELD DEFINITIONS
Logical Unit Number (LUN) – Byte 01, Bits 7 through 5
The tape drive only supports LUN 0. The value for this field must be 0.
Byte 01, Bit 0 – Fixed
This field specifies the type of write operation the tape drive is to perform, as
follows:
0
Write a single variable-length logical block
The length of this block is specified in the Transfer Length
field.
1
Write one or more fixed-length logical blocks
The number of blocks is specified in the Transfer Length
field.
Bytes 02 through 04 – Transfer Length
This field specifies the amount of data the tape drive is to write, as follows:
When the Fixed bit is set to 0 (write variable-length blocks), this field
contains the length of the logical block in bytes. The logical block can be any
size from 1 byte to 245,760 bytes (240 KB). The valid value for this field is
from 000001h to 03C000h (245,760 bytes).
When the Fixed bit is set to 1 (write fixed-length blocks), this field contains
the number of logical blocks to be written. The length of each block is either
the power-on default block length or the length specified with the currently
active MODE SELECT command (see page 9-5). Only block sizes that are
evenly divisible by four (that is, they end on a 4-byte boundary) are valid.
Note: When the value for the Transfer Length field is 0, no data is transferred and
the current position of the tape is not changed.
24.3 EXCEPTIONS AND ERROR CONDITIONS
The following exceptions and error conditions can occur with the WRITE
command.
OCTOBER 2008
VXA-2 TAPE DRIVE
24-3
CHAPTER 24 WRITE (0Ah)
Unrecoverable Error
If an unrecoverable write error occurs before the write operation completes,
the tape drive terminates the WRITE command and returns Check Condition
status. Data that remains in the buffer is not written to tape. The REQUEST
SENSE data is set as follows:
Valid
0 or 1
Sense Key
3h (Medium Error)
Information
bytes
If Valid=1, depend on the setting of the Fixed bit, as
follows:
ƒ If the Fixed bit is 0, equal the requested transfer length.
ƒ If the Fixed bit is 1, equal the difference between the
requested transfer length and the actual number of
logical blocks written.
ASC
00h
ASCQ
00h (Write Error)
Note: If another WRITE command is issued after an unrecoverable error occurs,
the tape drive returns Check Condition status with the sense key set to
Medium Error or Hardware Error and the command is not executed.
Early Warning Encountered
If early-warning is encountered during the WRITE command, or a WRITE
command is issued with the logical position between early-warning and EOP,
the drive attempts to finish writing all data. If all data can be written, the tape
drive returns Check Condition status after the command completes.
24-4
SCSI REFERENCE
Valid
1
EOM
1
Sense Key
0h (No Sense)
Information
bytes
000000h (no data was left unwritten)
ASC
00h
ASCQ
02h (End of Tape or End of Partition Detected)
FSC
2Ah, 2Dh
1009566-001
24.3 EXCEPTIONS AND ERROR CONDITIONS
PEOT or PEOP Encountered
If the physical end of tape (PEOT) or physical end of partition (PEOP) is
encountered, the tape drive terminates the WRITE command and returns
Check Condition status. Data that remains in the buffer is not written to tape.
The REQUEST SENSE data is set as follows:
Valid
0 or 1
EOM
1
Sense Key
Dh (Volume Overflow)
Information
Bytes
If Valid=1, depend on the setting of the Fixed bit, as
follows:
ƒ If the Fixed bit is 0, the Information bytes equal the
requested transfer length.
ƒ If the Fixed bit is 1, the Information bytes equal the
difference between the requested transfer length and
the actual number of logical blocks written.
ASC
00h
ASCQ
02h (End of Tape or End of Partition Detected)
FSC
2Ah, 2Dh
Table 24-1 lists additional exceptions and error conditions that cause the tape
drive to return Check Condition status for the SPACE command.
Table 24-1 REQUEST SENSE data for WRITE command errors and exceptions
Sense
Key
ASC
ASCQ Description
(Byte 12) (Byte 13)
02h
04h
01h
Not Ready. The tape drive is in the process of initializing itself.
02h
04h
03h
Not Ready. The tape drive requires manual intervention.
02h
3Ah
00h
Not Ready. The command requires a tape and no tape is present.
03h
30h
02h
Medium Error. The format of the currently loaded tape is not
compatible with the tape drive or the tape drive firmware.
0h
31h
00h
Medium Error. The format of the currently loaded tape is corrupted.
0h
50h
00h
Medium Error. Write failure after retry limit (specified in MODE
SELECT) was exceeded.
4h
15h
01h
Hardware Error. The tape drive cannot properly position the media.
OCTOBER 2008
VXA-2 TAPE DRIVE
24-5
CHAPTER 24 WRITE (0Ah)
Table 24-1 REQUEST SENSE data for WRITE command errors and exceptions (continued)
Sense
Key
ASC
ASCQ Description
(Byte 12) (Byte 13)
5h
24h
00h
Illegal Request. Invalid field in CDB. This error is a result of any of the
following:
ƒ The Fixed bit is set to 0 and the Transfer Length is not within the range
specified by the READ BLOCK LIMITS command.
ƒ The Fixed bit is set to 1 and the Block Length specified in the MODE
SELECT command is set to 0.
ƒ The Transfer Length exceeds 03C000h (245,760 bytes) for a
variable-length write operation.
5h
50h
01h
Illegal Request. A WRITE command was issued at an invalid tape
position.
6h
30h
00h
Unit Attention. The currently loaded tape is incompatible with the
tape drive.
7h
27h
00h
Write Protect. A write operation was attempted on a data cartridge
that is write protected.
0Bh
47h
00h
Aborted Command. A SCSI parity error occurred during data transfer.
24-6
SCSI REFERENCE
1009566-001
25
WRITE BUFFER (3Bh)
Bit
Byte
00
7
6
5
4
3
2
1
0
0
0
1
1
1
0
1
1
Logical Unit Number
01
Mode
Buffer ID
02
03
Reserved
(MSB)
Buffer Offset
04
(LSB)
05
06
(MSB)
Parameter List Length
07
(LSB)
08
Control
09
25.1 ABOUT THIS COMMAND
The WRITE BUFFER command allows you to reprogram the tape drive’s
EEPROM by loading a new microcode file across the SCSI bus. You can obtain
microcode update files on diskettes from Tandberg Data Technical Support, or
you can download microcode files from the Tandberg Data web site
(www.tandbergdata.com).
The WRITE BUFFER command can also be used in concert with the READ
BUFFER command to perform diagnostic testing. See Notes on page 14-1.
Note: Compression should be disabled when using the WRITE BUFFER
command.
OCTOBER 2008
VXA-2 TAPE DRIVE
25-1
CHAPTER 25 WRITE BUFFER (3Bh)
25.1.1
Caution
CAUTIONS FOR USING THE WRITE BUFFER COMMAND
Be sure to heed these precautions when issuing the WRITE BUFFER command:
Be sure that the tape drive is reserved for the initiator’s exclusive use while WRITE
BUFFER commands are executing.
Do not power off the tape drive while WRITE BUFFER commands are executing.
If a hardware failure or power failure occurs during the execution of this
command and the Mode bit is set to 101b, the tape drive may not be operable.
You must reload the firmware to restore functionality.
25.1.2
ABORTING A WRITE BUFFER OPERATION
If necessary, you can abort a write buffer operation by sending an Abort
message to the tape drive or resetting the tape drive. Then, you can reissue the
WRITE BUFFER command or the entire sequence of WRITE BUFFER
commands.
Note:
If you are performing a microcode update (Mode = 101b), you must
abort the command before the tape drive begins reprogramming the
EEPROM.
25.2 CDB FIELD DEFINITIONS
Logical Unit Number (LUN) – Byte 01, Bits 7 through 5
The tape drive only supports LUN 0. The value for this field must be 0.
Byte 01, Bits 2 through 0 – Mode
This field specifies the mode used to write data to the buffer. Table 25-1 lists the
valid values for this field.
Table 25-1 Valid Mode settings for the WRITE BUFFER (3Bh) command
Mode Setting Description
010b
Data mode. Use this mode to write data to the tape drive’s data buffer during diagnostic
testing.
100b
Firmware download mode. If your system requires you to use multiple WRITE BUFFER
commands to transfer the microcode file in small blocks, use this mode to transfer all but
the last block of data. The transferred blocks of data are held in the buffer. No data is
saved to the tape drive’s EEPROM.
101b
Firmware save mode. If your system supports transferring the entire microcode file with a
single WRITE BUFFER command, use this mode to transfer the entire file to the tape drive
data buffer and save it to the EEPROM.
If your system requires you to use multiple WRITE BUFFER commands to transfer the
microcode file in small blocks, use this mode to transfer last block of the microcode file
and save it to the tape drive’s EEPROM.
25-2
SCSI REFERENCE
1009566-001
25.3 UPDATING THE TAPE DRIVE MICROCODE
Byte 02 – Buffer ID
The tape drive has only one buffer. The value for this field must be 0.
Bytes 03 through 05 – Buffer Offset
The value you specify for the Buffer Offset field specifies the number of bytes
into the buffer to begin writing the transferred data. The valid values for this
field are between 000000h and 200000h (2,097,152 bytes = 2 MB). The value
you specify for the Buffer Offset must conform to the value returned in the
Offset Boundary field of the Buffer Descriptor for the READ BUFFER
command (see “Byte 00 – Offset Boundary” on page 14-3).
Bytes 06 through 08 – Parameter List Length
This field specifies the number of bytes to be transferred by the WRITE
BUFFER command.
Note: The Parameter List Length plus the Buffer Offset must not exceed 200000h
(2,097,152 bytes), the value returned in the Buffer Capacity field of the
Buffer Descriptor for the READ BUFFER command (see “Bytes 01 through
03 – Buffer Capacity” on page 14-3).
25.3 UPDATING THE TAPE DRIVE MICROCODE
To load microcode using the WRITE BUFFER command, follow the steps
outlined below.
1. Send the WRITE BUFFER command with the following settings:
Mode:
101b or 100b
Buffer ID:
00h
Buffer Offset:
The current Buffer Offset equals the sum of the previous
Buffer Offset plus previous Parameter List Length. (This
sum must not exceed the total length of the microcode
file.)
If you are using multiple WRITE BUFFER commands, the
Buffer Offset for the first WRITE BUFFER command must
be 000000h.
Parameter
List Length:
Number of bytes to be sent
Note:
OCTOBER 2008
Depending on your system’s capability, you may need to use multiple
WRITE BUFFER commands to transfer the entire microcode file to the
tape drive. In this case, transfer all but the last block of data to the
buffer by issuing multiple WRITE BUFFER commands with the Mode
bit set to 100b.Then transfer the last block of data by issuing a WRITE
BUFFER command with the Mode bit to 101b.
VXA-2 TAPE DRIVE
25-3
CHAPTER 25 WRITE BUFFER (3Bh)
2. Transfer the number of bytes specified by the Parameter List Length. If you
are using multiple WRITE BUFFER commands, the Parameter List Length
value you specify with each WRITE BUFFER command must indicate only
the amount of data you are transferring with that command, not the total
length of the microcode file. Use the Buffer Offset field to specify the
starting point within the file for the block of data to be transferred.
3. When the tape drive receives a WRITE BUFFER command with the Mode
bit set to 101b, it processes the command, then disconnects from the SCSI
bus and validates the microcode data in the buffer. When validation is
complete, the tape drive reconnects to the SCSI bus and returns status.
During validation, the microcode data is checked for the correct header and
internal format, the proper number of files, and whether the tape drive’s
hardware and boot code support the new microcode.
4. Wait for the Command Complete message and check the status. If the status
is not Good, issue a REQUEST SENSE command to identify the problem.
5. After the new microcode is validated and command status returned, the
tape drive disables all SCSI processing while it programs the EEPROM with
the new microcode. When the programming is complete, the tape drive
performs a reset to run the new firmware. The machine state (including
MODE SELECT parameters) is set to the new power-on defaults, and the
tape drive performs its power-on self-test.
6. Following a successful restart, the tape drive returns Check Condition
status with the sense key set to Unit Attention (6h) to the first command it
receives from each initiator. The ASC and ASCQ fields will be set to 3Fh and
01h, respectively (new microcode loaded).
25-4
SCSI REFERENCE
1009566-001
25.4 EXCEPTIONS AND ERROR CONDITIONS
25.4 EXCEPTIONS AND ERROR CONDITIONS
Table 25-2 lists the exceptions and error conditions that cause the tape drive to
return Check Condition status for the WRITE BUFFER command.
Table 25-2 REQUEST SENSE data for WRITE BUFFER command errors and exceptions
Sense
Key
ASC
ASCQ Description
(Byte 12) (Byte 13)
5h
24h
00h
Illegal Request. Invalid field in the CDB. This error is a result of any of
the following:
ƒ The Mode field contains a value other than 010b (data mode), 100b
(firmware download), or 101b (firmware save mode).
ƒ The Buffer ID field is not set to 0.
ƒ The value in the Buffer Offset field is greater than the value in the
Buffer Capacity field of the READ BUFFER Buffer Descriptor.
ƒ The sum of the values in the Parameter List Length plus the Buffer
Offset field is greater than the value returned in the Buffer Capacity
field of the READ BUFFER Buffer Descriptor.
06h
3Fh
01h
Unit Attention. The tape drive firmware (microcode) has been
changed.
0Bh
47h
00h
Aborted Command. A SCSI parity error occurred during data transfer.
OCTOBER 2008
VXA-2 TAPE DRIVE
25-5
CHAPTER 25 WRITE BUFFER (3Bh)
Notes
25-6
SCSI REFERENCE
1009566-001
26
WRITE FILEMARKS (10h)
Bit
Byte
00
7
6
5
4
3
2
1
0
0
0
0
1
0
0
0
0
WSmk
Immed
Logical Unit Number
01
02
Reserved
(MSB)
Transfer Length
03
(LSB)
04
05
Short
Control
26.1 ABOUT THIS COMMAND
The WRITE FILEMARKS command causes the tape drive to write any data
remaining in the buffer from a previous WRITE command to tape and then to
write zero or more filemarks or setmarks to tape.
A write filemarks operation can be performed at the following logical tape
positions:
Tape Positioned at LBOT or LBOP. When writing to a tape positioned at the
logical beginning of tape (LBOT) or at the logical beginning of partition
(LBOP), the tape drive automatically writes a new LBOT pattern and then
writes the requested number of filemarks (or setmarks).
Appending Data. The tape drive can append filemarks (or setmarks) to
existing data as long as the tape is positioned at one of the following
locations:
End of data (EOD) mark
Beginning or end of a long filemark
Beginning or end of a setmark
If the tape is not positioned at one of these locations, the tape drive returns
Check Condition status with the sense key set to Illegal Request (5h).
OCTOBER 2008
VXA-2 TAPE DRIVE
26-1
CHAPTER 26 WRITE FILEMARKS (10h)
26.2 CDB FIELD DEFINITIONS
Logical Unit Number (LUN) – Byte 01, Bits 7 through 5
The tape drive only supports LUN 0. The value for this field must be 0.
Byte 01, Bit 1 – WSmk (Write Setmark)
This field specifies whether you want the tape drive to write setmarks or
filemarks at the current position, as follows:
0
Write filemarks at the current position
1
Write setmarks at the current position
Byte 01, Bit 0 – Immed
The value for this field determines when command status is returned to the
initiator, as follows:
0
Status is reported to the initiator when the WRITE
FILEMARKS command is completed.
All buffered data, filemarks, and setmarks are written to
the tape before the command is completed.
1
Status is reported to the initiator when the WRITE
FILEMARKS command CDB is validated by the tape drive.
This mode is valid only if the tape drive is operating in
buffered mode (see Byte 02, Bits 6 through 4 – Buffered
Mode on page 10-4).
Bytes 02 through 04 – Transfer Length
This field specifies the number of filemarks (or setmarks) to be written to tape.
Valid values for this field are from 0000h to 00FFh (0 to 255). A value of 0 results
in either of the following:
If the Immed bit is 0, no filemarks (or setmarks) are transferred and the data
in the buffer is written to the tape.
If the Immed bit is 1, no operation is performed, the logical position of the
tape remains unchanged, and the tape drive returns Good status.
Byte 05, Bit 7 – Short
The value for this field determines the size of the filemark written to tape, as
follows:
26-2
SCSI REFERENCE
0
Write a long filemark
1
Write a short filemark
1009566-001
26.3 EXCEPTIONS AND ERROR CONDITIONS
The tape drive ignores this field because there is no distinction between short
and long file marks. This field is supported for compatibility purposes only.
26.3 EXCEPTIONS AND ERROR CONDITIONS
The following exceptions and error conditions can occur with the WRITE
FILEMARKS command.
Early Warning Encountered
If early-warning is encountered during the WRITE FILEMARKS command, or
a WRITE FILEMARKS command is issued with the logical position between
early-warning and EOP, the drive attempts to finish writing all data. If all data
can be written, the tape drive returns Check Condition status after the
command completes.
Valid
1
EOM
1
Sense Key
0h (No Sense)
Information
bytes
000000h (no data was left unwritten)
ASC
00h
ASCQ
02h (End of Tape Detected)
FSC
2Ah
PEOT or PEOP Encountered
If the physical end of tape (PEOT) or physical end of partition (PEOP) is
encountered, the tape drive terminates the WRITE FILEMARKS command
and returns Check Condition status. The REQUEST SENSE data is set as
follows:
OCTOBER 2008
Valid
0 or 1
EOM
1
Information
bytes
If Valid=1, contain the difference between the requested
number of filemarks (or setmarks) and the actual number
of filemarks (or setmarks) written.
Sense Key
Dh (Volume Overflow)
ASC
00h
ASCQ
02h (End of Tape or End of Partition Detected)
FSC
2Dh
VXA-2 TAPE DRIVE
26-3
CHAPTER 26 WRITE FILEMARKS (10h)
Unrecoverable Error
If an unrecoverable write error occurs before the write filemarks operation
completes, the tape drive terminates the WRITE command and returns Check
Condition status. Data that remains in the buffer is not written to tape. The
REQUEST SENSE data is set as follows:
Valid
0 or 1
Sense Key
3h (Medium Error)
Information
bytes
If Valid=1, contain the difference between the requested
transfer length and the actual number of filemarks (or
setmarks) written.
ASC
0Ch
ASCQ
00h (Write Error)
Note: If another WRITE FILEMARKS command is issued after an unrecoverable
error occurs, the tape drive returns Check Condition status with the sense
key set to Medium Error or Hardware Error and the command is not
executed.
Table 26-1 lists additional exceptions and error conditions that cause the tape
drive to return Check Condition status for the SPACE command.
Table 26-1 REQUEST SENSE data for WRITE FILEMARKS command errors and exceptions
Sense
Key
ASC
ASCQ Description
(Byte 12) (Byte 13)
02h
04h
01h
Not Ready. The tape drive is in the process of initializing itself.
02h
04h
03h
Not Ready. The tape drive requires manual intervention.
02h
3Ah
00h
Not Ready. The command requires a tape and no tape is present.
03h
30h
02h
Medium Error. The format of the currently loaded tape is not
compatible with the tape drive or the tape drive firmware.
0h
31h
00h
Medium Error. The format of the currently loaded tape is corrupted.
0h
50h
00h
Medium Error. Write append error. Write failure after retry limit
(specified in MODE SELECT) was exceeded.
4h
15h
01h
Hardware Error. The tape drive cannot properly position the media.
5h
24h
00h
Illegal Request. Invalid field in CDB. The Transfer Length exceeds
00FFh (255) filemarks (or setmarks).
5h
50h
01h
Illegal Request. A WRITE command was issued at an invalid tape
position.
26-4
SCSI REFERENCE
1009566-001
26.3 EXCEPTIONS AND ERROR CONDITIONS
Table 26-1 REQUEST SENSE data for WRITE FILEMARKS command errors and exceptions (continued)
Sense
Key
ASC
ASCQ Description
(Byte 12) (Byte 13)
6h
30h
00h
Unit Attention. The currently loaded tape is incompatible with the
tape drive.
7h
27h
00h
Data Protect. A write operation was attempted on a data cartridge that
is write protected.
OCTOBER 2008
VXA-2 TAPE DRIVE
26-5
CHAPTER 26 WRITE FILEMARKS (10h)
Notes
26-6
SCSI REFERENCE
1009566-001
A
ERROR CODES
This appendix describes the error codes the tape drive reports over the SCSI
bus in response to a REQUEST SENSE command (see Chapter 18). These error
codes include the following error information:
The sense key (SK), Additional Sense Codes (ASCs), and Additional Sense
Code Qualifiers (ASCQs) associated with the error. The ASC and ASCQ
codes provide additional information for each sense key. See Table 18-1 on
page 18-4 for definitions of the sense keys.
The Tandberg Data-unique Fault Symptom Codes (FSCs). These codes can
be used to determine the nature of hardware and software errors and other
events. Each FSC code description also provides recommended error
recovery procedures (ERPs).
A.1
REQUEST SENSE INFORMATION
This section lists the possible combinations of values for the Additional Sense
Code (ASC) and the Additional Sense Code Qualifier (ASCQ) fields in the
Extended Sense data returned by the REQUEST SENSE (03h) command. Each
ASC and ASCQ combination is associated with one or more Sense Key values,
and one or more Fault Symptom Codes (FSCs). The FSC is an Tandberg
Data-unique byte that specifies the reason for the most recent Check
Condition status. It is returned in byte 18 in the Extended Sense data.
!
Important
The Fault Symptom Codes may change as new revisions of the tape
drive firmware become available. For this reason, be sure to check the
documentation provided with new firmware releases for the most
current list of codes.
For ease of reference, Table A-1 lists all of the possible ASC, ASCQ, Sense Key,
and FSC values returned by the tape drive, sorted in ascending ASC/ASCQ order.
Each combination of values is accompanied by one or more cause codes and
one or more error recovery procedure codes (ERPs). The ERPs are described in
Section A.2 on page A-11.
OCTOBER 2008
VXA-2 TAPE DRIVE
A-1
APPENDIX A ERROR CODES
Note: When two or more ERP codes are listed for a Fault Symptom Code,
perform the recovery procedures in the order listed.
Cause Key:
A = Application software
O = Operator
B = Bus (SCSI)
S=
System
D = Drive
T=
Tape
I=
Information message
Table A-1 ASC, ASCQ, FSC, and Sense Key data returned by the REQUEST SENSE command
ASC
ASCQ
FSC
SK
Cause
ERP
SCSI Error Message and Description
00h
00h
00h
0h
I
10
No additional sense. Success
(synchronous).
00h
00h
01h
0h
I
10
No additional sense. Success
(asynchronous).
00h
00h
03h
Bh
O
11
No additional sense. The operation
stopped.
00h
00h
04h
Bh
O
11
No additional sense. The operation
aborted.
00h
00h
09h
0h
I
10
No additional sense. Compression not
installed.
00h
00h
0Ah
0h
I
10
No additional sense. The buffer is full.
00h
00h
0Bh
0h
I
10
No additional sense. The buffer is empty.
00h
00h
0Ch
0h
I
10
No additional sense. The buffer is ready to
be emptied.
00h
00h
0Dh
0h
I
10
No additional sense. The buffer is ready to
be filled.
00h
00h
0Eh
0h
I
10
No additional sense. Data has been
written to buffer.
00h
00h
0Fh
0h
I
10
No additional sense. Marks have been
written to buffer.
00h
00h
10h
0h
I
10
No additional sense. Data has been
written to tape.
00h
00h
11h
0h
I
10
No additional sense. Marks have been
written to tape.
00h
00h
12h
0h
I
10
No additional sense. Data has been read
from the buffer.
00h
00h
13h
0h
I
10
No additional sense. Data has been read
from the tape.
A-2
SCSI REFERENCE
1009566-001
A.1 REQUEST SENSE INFORMATION
Table A-1 ASC, ASCQ, FSC, and Sense Key data returned by the REQUEST SENSE command (continued)
ASC
ASCQ
FSC
SK
Cause
ERP
SCSI Error Message and Description
00h
00h
14h
0h
I
10
No additional sense. A buffer flush is
required.
00h
00h
15h
0h
I
10
No additional sense. DMA transfer
completed well.
00h
00h
16h
0h
I
10
No additional sense. Compression
transfer completed well.
00h
00h
17h
0h
I
10
No additional sense. Device completed
well.
00h
00h
1Bh
0h
D
13, 12
No additional sense. The device failed.
00h
00h
1Ch
0h
D
13, 12
No additional sense. The Read/Write
DMA transfer failed.
00h
00h
1Eh
0h
I
10
No additional sense. Buffer overrun.
00h
00h
1Fh
0h
I
10
No additional sense. Buffer under run.
00h
00h
20h
0h
I
10
No additional sense. Speed request is
invalid.
00h
00h
22h
0h
I
10
No additional sense. Splice position
marker was detected.
00h
00h
23h
0h
I
10
No additional sense. Control packet was
detected.
00h
00h
24h
0h
I
10
No additional sense. Tape count was
detected.
00h
00h
25h
0h
I
10
No additional sense. Logical block address
is out of range.
00h
00h
26h
0h
I
10
No additional sense. Logical block address
was detected.
00h
00h
27h
0h
I
10
No additional sense. Logical block set was
detected.
00h
00h
2Eh
0h
I
11
No additional sense. Early warning was
detected (EOM bit).
00h
00h
31h
0h
I
10
No additional sense. Read out of range
00h
00h
38h
0h
I
10
No additional sense. Error not
implemented.
00h
00h
3Ah
0h
I
10
No additional sense. General failure.
00h
00h
3Bh
0h
I
10
No additional sense. Servo at position.
00h
00h
3Ch
0h
I
10
No additional sense. Splice done.
00h
00h
49h
0h
A, T, D
11
No additional sense. Incorrect length
during read error (SILI bit).
OCTOBER 2008
VXA-2 TAPE DRIVE
A-3
APPENDIX A ERROR CODES
Table A-1 ASC, ASCQ, FSC, and Sense Key data returned by the REQUEST SENSE command (continued)
ASC
ASCQ
FSC
SK
Cause
ERP
SCSI Error Message and Description
00h
00h
4Ch
4h
D
12
Hardware error. There was an illegal
memory access error.
00h
00h
4Fh
0h
I
10
No additional sense. Bad location.
00h
00h
50h
Bh
D
13, 12
00h
00h
51h
0h
I
10
No additional sense. Pause time out.
00h
00h
5Bh
0h
I
10
No additional sense. Unexpected
condition.
00h
00h
5Ch
0h
I
10
No additional sense. Marginal read error.
00h
00h
5Dh
3h
I
10
No additional sense.
00h
00h
61h
0h
I
10
No additional sense. Forced rewrite.
00h
00h
62h
0h
I
10
No additional sense. Marginal write error.
00h
01h
28h
0h
I
11
Filemark detected. A filemark was
encountered during a read, space, or
locate operation. The tape is positioned at
the EOT-side of the filemark.
00h
01h
41h
0h
I
11
Filemark read. A filemark was read during
a read operation. The tape is positioned at
the EOT-side of the filemark.
00h
02h
2Ah
0h
I
11
EOT detected. This error is a result of any
of the following:
ƒ LEOT was encountered during a read,
write, or write filemarks operation.
ƒ PEOT was encountered during a space,
locate, read, or verify operation.
ƒ EOT was encountered or partition size is
too big for tape.
00h
02h
2Dh
0h, 3h, Dh
I
11
EOP detected. This error is a result of any
of the following:
ƒ LEOP was encountered during a read,
write, or write filemarks operation.
ƒ PEOP was encountered during a space,
locate, read, or verify operation.
ƒ EOP was encountered or partition size is
too big for tape.
00h
03h
40h
0h
I
11
Setmark detected. A setmark was
encountered during a read, space, or
locate operation. The tape is positioned at
the EOT-side of the setmark.
A-4
SCSI REFERENCE
No additional sense. Bad data.
1009566-001
A.1 REQUEST SENSE INFORMATION
Table A-1 ASC, ASCQ, FSC, and Sense Key data returned by the REQUEST SENSE command (continued)
ASC
ASCQ
FSC
SK
Cause
ERP
SCSI Error Message and Description
00h
04h
29h
0h
I
11
BOT detected. PBOT was encountered
during a space or locate operation.
00h
04h
2Bh
0h
I
11
BOP detected. PBOP was encountered
during a space or locate operation.
00h
05h
08h
8h
I
6
Blank check. Media not initialized (blank
tape).
00h
05h
2Ch
8h
I
11
EOD detected. End of data detected.
00h
05h
68h
3h
I, A, O
14, 11
Data terminated. Data terminated due to
a prior write failure.
00h
06h
04h
Bh
O
11
I/O process terminated. SCSI data transfer
aborted.
00h
17h
—
2h
O
9
Expired cleaning tape. The cleaning tape
does not have sufficient unused cleaning
material to perform the cleaning. Use a
new cleaning cartridge.
00h
17h
67h
1h
I, T, D
9, 6
Cleaning requested by tape drive. The
tape drive has requested a cleaning.
03h
02h
4Dh
3h
T, D
9, 6, 12
Excessive write errors. The tape drive
experienced excessive write errors.
04h
00h
4Bh
2h
O, T, D
7
Logical unit not ready. No additional
sense data is available.
04h
01h
02h
2h
O
11
Logical unit becoming ready. Logical unit
is not ready, but is in process of becoming
ready (rewinding or loading tape).
04h
01h
4Bh
2h
O, T, D
7
Logical unit becoming ready. Logical unit
is not ready, but is in process of becoming
ready (rewinding or loading tape).
04h
02h
07h
2h
O
7
Logical unit not ready. Initialization
required. The specified logical unit is not
ready.The drive is in the process of ejecting
a cartridge.
04h
03h
—
2h
O, T, D
7
Logical unit not ready. Manual
intervention required. The specified
logical unit is not ready. Operator
intervention is required.
0Ch
00h
18h
4h
T, D
9, 6, 12
0Ch
00h
1Ch
3h
T, D
9, 14, 12 Read/write transfer error.
0Ch
00h
2Fh
4h
D
9, 6, 12
Write error. General write error detected.
0Ch
00h
42h
3h
T, D
9, 6, 12
Write error. Gap write error.
OCTOBER 2008
General hardware failure.
VXA-2 TAPE DRIVE
A-5
APPENDIX A ERROR CODES
Table A-1 ASC, ASCQ, FSC, and Sense Key data returned by the REQUEST SENSE command (continued)
ASC
ASCQ
FSC
SK
Cause
ERP
SCSI Error Message and Description
0Ch
00h
4Dh
3h
T, D
9, 6, 12
Permanent write errors. Permanent write
error. The tape drive experienced excessive
write errors.
0Ch
00h
52h
3h
T, D
9, 6, 12
Write error. BOD gap write error.
0Ch
00h
53h
3h
T, D
9, 6, 12
Write error. EOD gap write error.
0Ch
00h
54h
3h
T, D
9, 6, 12
Write error. Mark gap write error.
0Ch
00h
55h
3h
T, D
9, 6, 12
Write error. PM gap write error.
0Ch
00h
56h
3h
T, D
9, 6, 12
Write error. Flush gap write error.
0Ch
00h
57h
3h
T, D
9, 6, 12
Write error. Erase gap write error.
0Ch
00h
5Dh
3h
T, D
9, 6, 12
Write error.
11h
00h
30h
4h
T, D
9, 14, 12 Unrecovered read error. General read
error detected.
11h
00h
33h
3h
T, D
9, 14, 12 Unrecovered read error. An
uncorrectable block was encountered
during a read, space, or locate operation.
11h
00h
4Eh
3h
T, D
9, 14, 12 Permanent read error. A hardware error
was detected during a read operation.
11h
02h
1Ah
4h
T, D
9, 14, 12 Read CRC too long (decompression
error). Read decompression CRC failed.
11h
02h
32h
3h
T, D
9, 14, 12 Read CRC too long (decompression
error). Read decompression CRC failed.
14h
00h
3Eh
3h
T, D
9, 12, 14 Recorded entity not found. A Medium
Error was detected during a read, space, or
locate operation. The specified logical
block address was not found.
14h
03h
—
—
—
—
EOD not found. Not used.
14h
04h
—
—
—
—
Block sequence error. Not used.
15h
01h
1Dh
3h
T, D
9, 6, 12
Mechanical position error. Servo failure.
15h
01h
3Dh
3h
T, D
9, 6, 12
Mechanical position error. Servo
mispositioned.
15h
01h
45h
4h
T, D
9, 6, 12
Mechanical position error. Servo time
out.
15h
01h
58h
3h
T, D
9, 6, 12
Mechanical position error. Servo loop
check.
15h
01h
5Ah
3h
T, D
9, 6, 12
Mechanical position error. Servo drum
check.
15h
01h
5Fh
3h
T, D
9, 6, 12
Mechanical position error. Broken tape.
A-6
SCSI REFERENCE
1009566-001
A.1 REQUEST SENSE INFORMATION
Table A-1 ASC, ASCQ, FSC, and Sense Key data returned by the REQUEST SENSE command (continued)
ASC
ASCQ
FSC
SK
Cause
ERP
1Ah
00h
48h
5h
A, O
4
Parameter length error. This error is a
result of any of the following:
ƒ Parameter List Length error in the MODE
SELECT CDB.
ƒ Illegal transfer length in CDB.
20h
00h
48h
5h
A, O
4
Invalid command op code. Illegal
operation code.
21h
00h
—
—
—
—
LBA out of range. Not used.
24h
00h
48h
5h
A, O
4
Invalid field in CDB. An invalid field was
detected in the CDB.
25h
00h
48h
5h
A, O
4
Logical unit not supported. Logical unit
specified in the CDB not supported.
26h
00h
48h
5h
A, O
4
Invalid field in parameter list. This error is
a result of any of the following:
ƒ Invalid field in the MODE SELECT
Parameter List.
ƒ Conflict between Density Code and Data
Compression page in MODE SELECT.
26h
01h
48h
5h
A, O
4
Parameter not supported. There is an
invalid value for an unsupported
parameter.
26h
02h
66h
5h
A, D
26h
02h
6Bh
5h
I, A, O
11
27h
00h
47h
7h
T, D
5, 6, 12
Write protected. The data cartridge is
write protected.
28h
00h
0h
6h
I
10, 11
Not ready to ready transition. A new tape
load has occurred and the media may have
changed.
29h
00h
0h
6h
I
10, 11
Power on or reset. The drive has been
power cycled or a SCSI reset has occurred.
2Ah
01h
0h
6h
I
10, 11
Mode Parameters changed. MODE
SELECT parameters have been changed.
OCTOBER 2008
SCSI Error Message and Description
4, 15, 12 Parameter value invalid. This error is a
result of any of the following:
ƒ A WRITE BUFFER parameter value was
invalid.
ƒ The code header, EEPROM image, or
control load image was not valid when
loading firmware.
Hardware is incompatible with firmware
code file.
VXA-2 TAPE DRIVE
A-7
APPENDIX A ERROR CODES
Table A-1 ASC, ASCQ, FSC, and Sense Key data returned by the REQUEST SENSE command (continued)
ASC
ASCQ
FSC
SK
Cause
ERP
SCSI Error Message and Description
2Ah
02h
0h
6h
I
10, 11
30h
00h
34h
3h
T, D
9, 14, 12 Incompatible medium. (The media does
not have a compatible logical format
header record.)
ƒ Incompatible media was ejected after a
LOAD command was issued.
ƒ Incompatible media was rejected after
the data cartridge was inserted.
30h
00h
35h
3h
T, D
9, 14, 12 Incompatible medium. (The media does
not have a compatible logical format
directory header.)
ƒ Incompatible media was ejected after a
LOAD command was issued.
ƒ Incompatible media was rejected after
the data cartridge was inserted.
30h
00h
36h
3h
T, D
9, 14, 12 Incompatible medium. (The media has a
bad logical format header revision.)
ƒ Incompatible media was ejected after a
LOAD command was issued.
ƒ Incompatible media was rejected after
the data cartridge was inserted.
30h
00h
37h
3h
T, D
9, 14, 12 Incompatible medium. (The media has a
bad logical format directory revision.)
ƒ Incompatible media was ejected after a
LOAD command was issued.
ƒ Incompatible media was rejected after
the data cartridge was inserted.
30h
00h
63h
3h, 6h
T, D
9, 6, 12
Incompatible medium. The cartridge
contains incompatible media. This error is
a result of any of the following:
ƒ Incompatible media was ejected after a
LOAD command was issued.
ƒ Incompatible media was rejected after
the data cartridge was inserted.
30h
02h
37h
3h
T, D
9, 6, 12
Incompatible format. This error is a result
of any of the following:
ƒ The tape format is incompatible with the
tape drive.
ƒ The tape format is incompatible with the
command.
A-8
SCSI REFERENCE
Log Parameters changed. LOG SELECT
parameters have been changed.
1009566-001
A.1 REQUEST SENSE INFORMATION
Table A-1 ASC, ASCQ, FSC, and Sense Key data returned by the REQUEST SENSE command (continued)
ASC
ASCQ
FSC
SK
Cause
ERP
30h
02h
69h
3h
T, D
9, 6,
14, 12
Media format incompatible.
30h
03h
07h
02h
T, O
7
Cleaning cartridge installed.
31h
00h
65h
3h
T, D
39h
00h
48h
5h
A, O
4
Saving parameters not supported. MODE
SENSE does not support saving of
parameters to non-volatile RAM.
3Ah
00h
21h
2h
O
7
Medium not present. Drive is not ready.
Command requires a tape and no tape is
present.
3Dh
00h
48h
5h
A, O
4
Invalid bits in Identify message. An illegal
bit was set in the Identify message received
by the tape drive.
3Fh
00h
5Eh
6h
S, O
11
Operating conditions changed. The drive
is over temperature. Cartridges are
automatically ejected until temperature
returns to normal range.
3Fh
01h
0h
6h
I
10
Microcode changed. New microcode
(firmware) was loaded.
3Fh
02h
—
—
—
—
New operation definition. Not used.
3Fh
03h
0h
6h
I
10
Inquiry data changed. Data in the
Standard Inquiry Page has been altered.
44h
00h
05h
4h
T, D
8, 9, 6,
12
Internal target fail. (Software error.)
Firmware consistency failure.
44h
00h
06h
4h
T, D
8, 9, 6,
12
Internal target fail. (System error.)
Firmware consistency failure.
44h
00h
39h
4h
T, D
8, 9, 6,
12
Internal target fail. (System time out.)
Firmware consistency failure.
44h
00h
43h
4h
D
8, 9, 12
Internal target fail. (Data path time out.)
Firmware consistency failure.
44h
00h
44h
4h
D
8, 9, 12
Internal target fail. (Control time out.)
Firmware consistency failure.
44h
00h
46h
4h
B, D
8, 9, 12
Internal target fail. (SCSI time out.)
Firmware consistency failure.
44h
00h
6Ah
4h
T, D
9, 6, 12
Hardware is broken.
45h
00h
19h
Bh
B, D
8, 9, 11, Select/Reselect fail. A SCSI selection or
12
reselection failed.
OCTOBER 2008
SCSI Error Message and Description
9, 14, 12 Medium format corrupted. Media
directory corrupted by power failure.
VXA-2 TAPE DRIVE
A-9
APPENDIX A ERROR CODES
Table A-1 ASC, ASCQ, FSC, and Sense Key data returned by the REQUEST SENSE command (continued)
ASC
ASCQ
FSC
SK
Cause
47h
00h
04h
Bh
B, D
8, 9, 11, SCSI parity error. The command was
12
aborted because of a SCSI bus parity error.
47h
00h
4Ah
Bh
B, D
8, 9, 11, SCSI parity error. The command was
12
aborted because of a SCSI bus parity error.
48h
00h
04h
Bh
B, D
8, 9, 11, Initiator detected error. Operation
12
aborted.
49h
00h
—
—
B, D
8, 9, 11,
12
4Ah
00h
19h
Bh
B, D
8, 9, 11, Command phase error. A SCSI phase
12
error occurred during the command phase.
4Bh
00h
19h
Bh
B, D
8, 9, 11, Data phase error. A SCSI phase error
12
occurred during the data phase.
4Ch
00h
48h
5h
D
4Eh
00h
2h
5h
B, D
8, 9, 11,
12
Overlapped commands attempt.
Overlapped commands attempted. Bad
initiator-target-LUN (ITL) nexus.
50h
00h
3Fh
3h
T, D
9, 6, 12
Write append error. Write failure after
retry limit (specified in MODE SELECT) was
exceeded because the splice position
marker not found.
50h
01h
3Fh
3h, 5h,
T, D
9, 6, 12
Write append position error. This error is
a result of any of the following:
ƒ Write failure after retry limit (specified in
MODE SELECT) was exceeded.
ƒ Write append position error or illegal
position to format partitions or erase.
51h
00h
57h
3h
T, D
9, 6, 12
Erase fail. Unable to cleanly erase data
from tape because of an erase gap write
error.
53h
00h
0h
5h
I
11
Media load eject fail. Media removal
prevented.
53h
00h
5Dh
2h
I
11
Media load eject fail. Media removal
prevented.
53h
01h
0h
5h
I
11
Media unload fail. Media removal
prevented.
5Ah
01h
0h
6h
O
10
Operator remove media required. The
operator requested media removal.
A-10
SCSI REFERENCE
ERP
SCSI Error Message and Description
Invalid message error. The drive received
an unknown SCSI message.
8, 11, 12 Logical unit failed self config. The
bootblock code is active and normal
functional code cannot be started.
1009566-001
A.2 ERROR RECOVERY PROCEDURES
Table A-1 ASC, ASCQ, FSC, and Sense Key data returned by the REQUEST SENSE command (continued)
ASC
ASCQ
FSC
SK
Cause
ERP
SCSI Error Message and Description
5Bh
01h
0h
6h
I
11
Threshold condition met. Log threshold
met. (For additional information about this
error, look at the Log Parameter Page Code
and Log Parameter Code bytes in the
REQUEST SENSE data.)
5Bh
02h
0h
1h
I
11
Log counter at max. Log parameter
overflow. (A cumulative counter reached its
maximum value of all FFs.)
5Dh
00h
60h
0h, 1h, 6h
T, D
11
TapeAlert exception. This error is a result
of any of the following:
ƒ A tape drive component has exceeded its
expected operational lifetime.
ƒ TapeAlert asynchronous notification.
ƒ TapeAlert asynchronous notification test.
A.2
ERROR RECOVERY PROCEDURES
The following table describes the error recovery procedures (ERPs)
recommended for each Fault Symptom Code listed in the previous section.
Caution
Some recovery procedures advise you to reset the tape drive. Before performing
a reset, make sure there is no SCSI activity on the SCSI bus to which the drive is
connected. Resetting a device on an active bus may disrupt communications.
Table A-2 Recommended error recovery procedures
ERP
Recommended error recovery procedure
1
Issue a REWIND command and retry the operation.
2
Issue a SPACE command to space backward over a block or a filemark.
3
Reissue the failed command or command sequence.
4
Correct the errors in the CDB bytes or parameter data.
5
Move the write protect switch on the data cartridge to write enable the tape.
6
Repeat the operation with a new data cartridge.
7
Insert a data cartridge into the tape drive.
8
Perform one of the following actions:
ƒ Power the tape drive off and back on again.
ƒ Send a SCSI bus reset (“hard” reset).
ƒ Reset the tape drive by holding down the eject button for >10 seconds, and then releasing it.
9
Clean the tape drive and repeat the operation.
OCTOBER 2008
VXA-2 TAPE DRIVE
A-11
APPENDIX A ERROR CODES
Table A-2 Recommended error recovery procedures
ERP
Recommended error recovery procedure
10
No action is necessary.
11
User should determine what recovery procedure to follow.
12
The tape drive requires maintenance.
13
ƒ
ƒ
ƒ
ƒ
ƒ
ƒ
14
Repeat the operation with a different data cartridge; the tape drive cannot read the tape.
15
Reload firmware.
A-12
Perform one of the following actions:
Issue a REWIND, SPACE, LOAD/UNLOAD, or LOCATE command
Press the eject button
Power the tape drive off and back on again
Send a SCSI bus reset (“hard” reset)
Reissue the failed command or command sequence.
SCSI REFERENCE
1009566-001
INDEX
#
2’s complement, definition
WRITE FILEMARKS
9-26
A
Aborted Command (Bh) sense key,
definition 18-5
allocation length
definition 1-7
INQUIRY 4-2
LOG SENSE 8-4
MODE SENSE 10-3
READ BUFFER 14-3
RECEIVE DIAGNOSTIC RESULTS 16-1
REQUEST SENSE 18-1
appending data, legal tape positions 24-2
ASC and ASCQ
ERASE 3-3
for all sense keys A-1 to A-11
for threshold met criteria (TMC) bit 7-7
INQUIRY 4-11
LOAD/UNLOAD 5-4
LOCATE 6-3
LOG SELECT 7-8 to 7-8
LOG SENSE 8-20
MODE SELECT 9-23, 9-28 to 9-29
MODE SENSE 10-25
READ 12-3 to 12-8
READ BUFFER 14-4
READ POSITION 15-4
REQUEST SENSE 18-6
REWIND 20-2
SPACE 22-3 to 22-7
TEST UNIT READY 23-2
values following a reset 2-12 to 2-13
values for CDB format errors 1-7
WRITE 24-3 to 24-6
WRITE BUFFER 25-5
OCTOBER 2008
26-3 to 26-5
B
Blank Check (8h) sense key, definition 18-5
Block Descriptor, MODE SELECT
command 9-4 to 9-5
Block Descriptor, MODE SENSE
command 10-5 to 10-6
Block Length field 9-5, 10-6
Buffered Mode field
MODE SELECT 9-3
MODE SENSE 10-4
buffered write operation 24-2
Bus Device Reset (0Ch) message 2-12
Busy status 1-9
C
cartridges
data capacities 2-1
effect of changing 2-10
effect on reset 2-12
loading 2-2
unloading 2-2 to 2-3
CDB
See command descriptor block (CDB)
Check Condition status 1-8
cleaning required
CLN (Clean) bit 18-8
REQUEST SENSE indicators 18-8
code updates
See microcode
command descriptor block (CDB)
control byte format 1-5
field definitions 1-5 to 1-7
general format 1-4 to 1-5
VXA-320 TAPE DRIVE
I-1
INDEX
operation code format 1-5
command protocol, description 1-2
commands
differences between VXA-1 and VXA-2 1-10
ERASE 3-1 to 3-3
field definitions, general 1-5 to 1-7
format errors 1-7
general format 1-4 to 1-7
INQUIRY 4-1 to 4-11
LOAD/UNLOAD 5-1 to 5-4
LOCATE 6-1 to 6-4
LOG SELECT 7-1 to 7-8
LOG SENSE 8-1 to 8-19
MODE SELECT 9-1 to 9-29
MODE SENSE 10-1 to 10-25
PREVENT/ALLOW MEDIUM
REMOVAL 11-1 to 11-2
READ 12-1 to 12-8
READ BLOCK LIMITS 13-1 to 13-2
READ BUFFER 14-1 to 14-4
READ POSITION 15-1 to 15-4
RECEIVE DIAGNOSTIC
RESULTS 16-1 to 16-4
RELEASE UNIT 17-1 to 17-2
REQUEST SENSE 18-1 to 18-10
RESERVE UNIT 19-1 to 19-2
REWIND 20-1 to 20-3
SEND DIAGNOSTIC 21-1 to 21-4
six-byte CDB format 1-4
SPACE 22-1 to 22-7
status byte returned 1-8 to 1-9
ten-byte CDB format 1-5
TEST UNIT READY 23-1 to 23-2
WRITE 24-1 to 24-6
WRITE BUFFER 25-1 to 25-5
WRITE FILEMARKS 26-1 to 26-5
communication interface, description 1-1
compression
disabling 9-11 to 9-12
MODE SELECT Data Compression
page 9-11 to 9-12
MODE SENSE Data Compression
page 10-11 to 10-12
using 2-3
Compression Statistics page, LOG SENSE
parameter codes 8-12
control byte format 1-5
Control Mode page
MODE SELECT command 9-9 to 9-11
MODE SENSE command 10-9 to 10-11
I-2
SCSI REFERENCE
D
data cartridges
See cartridges
data compression
See compression
Data Compression page
MODE SELECT command 9-11 to 9-12
MODE SENSE command 10-11 to 10-12
Data Protect (7h) sense key, definition 18-5
data transfer efficiency, maximizing 2-4 to 2-5
DCC (Data Compression Capable) bit 9-12,
10-12
DCE (Data Compression Enable) bit 9-11, 10-11
DDE (Data Decompression Enable) bit 9-12,
10-12
Density Code field
error codes for illegal settings 9-5
indicating data format of current tape 10-5
using to specify data format 9-4
Device Configuration page
MODE SELECT command 9-13 to 9-16
MODE SENSE 10-12 to 10-15
device drivers, converting existing 1-10
Device Identification page 4-9 to 4-10
Diagnostic Parameter Header
RECEIVE DIAGNOSTIC RESULTS 16-2
SEND DIAGNOSTIC 21-3
diagnostic results, retrieving 16-2 to 16-4
diagnostic tests, specifying 21-3 to 21-4
Disconnect-Reconnect page 9-7 to 9-9
MODE SELECT command 9-7 to 9-9
MODE SENSE command 10-7 to 10-9
Drive Statistics page, LOG SENSE parameter
codes 8-18 to 8-19
DTDC (Data Transfer Disconnect Control)
field 9-9, 10-9
E
Environmental Counter page, LOG SENSE
parameter codes 8-13
EOD (end of data)
description 2-5
detected during locate 6-4
detected during read 12-5
detected during space 22-5
position to during space 22-2
1013599
INDEX
ERASE (19h) command
description 3-1
exceptions and errors 3-3
field definitions 3-2
legal tape positions 3-3
error codes A-1 to A-11
See also ASC and ASCQ
error recovery procedures (ERP) A-11
errors in CDB format 1-7
extended sense bytes 18-2 to 18-9
F
Fault Symptom Codes (FSCs)
definition A-1
for all sense keys A-1 to A-11
in WRITE BUFFER 25-5
in WRITE FILEMARKS 26-3 to 26-5
list A-1 to A-11
reported by REQUEST SENSE 18-7
filemarks
description 2-4
detected during read 12-4
detected during space 22-3
legal tape positions for writing 26-1
writing with WRITE FILEMARKS
command 26-1
firmware
See microcode
fixed-length logical blocks
block length 9-5, 10-6
specifying for read operations 12-2
specifying for write operations 24-3
format errors in CDBs 1-7
formats
See Density Code field
FSC
See Fault Symptom Codes (FSCs)
G
Good status
1-8
H
Hardware Error (4h) sense key, definition 18-4
I
Illegal Request (5h) sense key
OCTOBER 2008
definition 18-4
REQUEST SENSE 9-5
sense key specific data 18-6
INQUIRY (12h) command
description 4-1
Device Identification page (83h) 4-9 to 4-10
differences between VXA-1 and VXA-2 1-10
exceptions and errors 4-11
field definitions 4-1 to 4-2
Original Inquiry Data page (C0h) 4-10
Product Identification 4-5
Standard Inquiry Data 4-3 to 4-6
summary of inquiry data returned 4-2
Supported Vital Product Data page
(00h) 4-6 to 4-7
Unit Serial Number page (80h) 4-8
L
LBOP (logical beginning of partition) 2-6
LEOP (logical end of partition) 2-6
LOAD/UNLOAD (1Bh) command
description 5-1 to 5-2
effect of PREVENT/ALLOW MEDIUM
REMOVAL 11-2
exceptions and errors 5-4
field definitions 5-2 to 5-4
response to a tape motion command 5-2
loading a data cartridge 2-2
LOCATE (2Bh) command
description 6-1
exceptions and errors 6-3
field definitions 6-2 to 6-3
log parameter format 8-5 to 8-8
log parameters
LOG SELECT 7-5
LOG SENSE 8-5 to 8-19
LOG SELECT (4Ch) command
description 7-1
exceptions and errors 7-8 to 7-8
field definitions 7-2 to 7-3
log parameters 7-5 to 7-8
Parameter List Header 7-4
Parameter List Length 7-3
Read Error Counters page 7-6
Write Error Counters page 7-6
LOG SENSE (4Dh) command
Compression Statistics page (30h) 8-12
description 8-1
Drive Statistics page (3Ch) 8-18 to 8-19
VXA-320 TAPE DRIVE
I-3
INDEX
Environmental Counter page (36h) 8-13
exceptions and errors 8-20
field definitions 8-2 to 8-4
log parameters 8-5 to 8-19
log parameters returned 8-4 to 8-19
Parameter List Header 8-5
Read Error Counters page (03h) 8-8
Supported Log Pages page (00h) 8-8
supported page codes 8-3
Tape Capacity page (31h) 8-13
Tape Last FSC page (39h) 8-16 to 8-18
Tape Usage page (37h) 8-14 to 8-16
TapeAlert page (2Eh) 8-9 to 8-12
Write Error Counters page (02h) 8-8
logical blocks
spacing over fixed-length blocks 22-2
spacing over variable-length blocks 22-2
specifying fixed-length or
variable-length 2-3
M
maximum block length 13-2
media
types supported 10-4
See also cartridges
Medium Error (3h) sense key, definition 18-4
Medium Partition page
MODE SELECT command 9-16 to 9-21
MODE SENSE command 10-16 to 10-17
microcode, updating using WRITE BUFFER
command 25-3 to 25-4
minimum block length 13-2
Miscompare (Eh) sense key, definition 18-5
MODE SELECT (15h) command
Block Descriptor 9-4 to 9-5
Block Length field 9-5
Buffered Mode field 9-3
Control Mode page (0Ah) 9-9 to 9-11
Data Compression page (0Fh) 9-11 to 9-12
DCE bit 9-11
DDE bit 9-12
Density Code field 9-4
description 9-1
Device Configuration page
(10h) 9-13 to 9-16
differences between VXA-1 and VXA-2 1-10
Disconnect-Reconnect page (02h) 9-7 to 9-9
DTDC field 9-9
I-4
SCSI REFERENCE
exceptions and error
conditions 9-28 to 9-29
field definitions 9-1 to 9-3
Medium Partition page (11h) 9-16 to 9-21
MRIE field 9-23
Parameter List Header 9-3
parameter list length 9-2 to 9-3
Read-Write Error Recovery page
(01h) 9-6 to 9-7
RLEC bit 9-10
RSmk bit 9-15
specifying fixed or variable-length
blocks 9-5
TapeAlert page (1Ch) 9-22 to 9-24
Vendor Unique Parameters Page 1 page
(21h) 9-24 to 9-28
MODE SENSE (1Ah) command
Block Descriptor 10-5 to 10-6
Block Length field 10-6
Buffered Mode field 10-4
Control Mode page (0Ah) 10-9 to 10-11
Data Compression page
(0Fh) 10-11 to 10-12
DCE bit 10-11
DDE bit 10-12
Density Code field 10-5
description 10-1
Device Configuration page
(10h) 10-12 to 10-15
differences between VXA-1 and VXA-2 1-10
Disconnect-Reconnect page
(02h) 10-7 to 10-9
DTDC field 10-9
exceptions and error conditions 10-25
field definitions 10-1 to 10-3
log parameters returned 10-3 to 10-25
Medium Partition page (11h) 10-16 to 10-17
Medium Type field 10-4
MRIE field 10-19
Parameter List Header 10-3 to 10-5
Read-Write Error Recovery page
(01h) 10-6 to 10-7
RLEC bit 10-10
RSmk bit 10-14
specifying fixed-length or variable-length
blocks 10-6
supported page codes 10-2
TapeAlert page (1Ch) 10-17 to 10-20
Vendor Unique Parameters Page 1 page
(21h) 10-20 to 10-23
1013599
INDEX
Vendor Unique Parameters Page 2 page
(22h) 10-24
MRIE
reporting options 9-22, 10-18
setting 9-23, 10-19
N
No Diagnostic Results Available page 16-4
No Sense (0h) sense key, definition 18-4
Not Ready (2h) sense key, definition 18-4
O
operation code format 1-5
operations, implementing 2-1
Original Inquiry Data page 4-10
P
Parameter List Header
LOG SELECT 7-4
LOG SENSE 8-5
MODE SELECT 9-3
MODE SENSE 10-3 to 10-5
parameter list length
LOG SELECT 7-3
MODE SELECT 9-2 to 9-3
SEND DIAGNOSTIC 21-3
partitions
Medium Partition page 9-16 to 9-21,
10-16 to 10-17
numbering 9-16
using 2-5 to 2-9
PBOP (physical beginning of partition)
description 2-6
detected during space 22-5
PBOT (physical beginning of tape), detected
during space 22-5
PEOP (physical end of partition)
description 2-6
detected during locate 6-3
detected during read 12-5
detected during space 22-4, 22-6
detected during write 24-5
PEOT (physical end of tape)
detected during locate 6-3
detected during read 12-5
detected during space 22-4, 22-6
OCTOBER 2008
detected during write 24-5
detected during write filemarks 26-3
physical path communications 1-1
power-on reset 2-11
PREVENT/ALLOW MEDIUM REMOVAL (1Eh)
command
description 11-1
effect on LOAD/UNLOAD 11-2
effect on unload button 11-2
field definitions 11-2
R
READ (08h) command
description 12-1
exceptions and errors 12-3 to 12-8
field definitions 12-1 to 12-3
SILI (Suppress Illegal Length Indication)
bit 12-2
specifying fixed-length or variable-length
block reads 12-2
READ BLOCK LIMITS (05h) command
data returned 13-2
description 13-1
field definitions 13-1
maximum block length 13-2
minimum block length 13-2
READ BUFFER (3Ch) command
buffer descriptor 14-3
description 14-1
exceptions and errors 14-4
field definitions 14-2 to 14-3
Read Error Counters page
LOG SELECT command 7-6
LOG SENSE parameter codes 8-8
READ POSITION (34h) command
description 15-1
exceptions and errors 15-4
field definitions 15-1
Read Position data 15-2 to 15-4
Read-Write Error Recovery page
MODE SELECT 9-6 to 9-7
MODE SENSE 10-6 to 10-7
RECEIVE DIAGNOSTIC RESULTS (1Ch)
command
description 16-1
Diagnostic Parameter Header 16-2
field definitions 16-1
No Diagnostic Results Available Page
(FFh) 16-4
VXA-320 TAPE DRIVE
I-5
INDEX
returning diagnostic data 16-2 to 16-4
Self Test page (F0h) 16-3
Supported Diagnostic Pages page
(00h) 16-3
Recovered Error (1h) sense key, definition 18-4
RELEASE UNIT (17h) command
description 17-1
field definitions 17-1
Report Log Exception Condition (RLEC)
field 9-10, 10-10
Report Setmarks field 9-15, 10-14
REQUEST SENSE (03h) command
ASC and ASCQ values A-1 to A-11
CLN (Clean) bit 18-8
description 18-1
extended sense bytes 18-2 to 18-9
Fault Symptom Codes (FSCs) 18-7,
A-1 to A-11
field definitions 18-1
pending status 18-10
sense key definitions 18-4 to 18-5
unit sense bytes 18-8
Reservation Conflict status 1-9
RESERVE UNIT (16h) command
description 19-1
exceptions and errors 19-2
field definitions 19-1 to 19-2
resetting the tape drive 2-11 to 2-13
REWIND (01h) command
CDB field definitions 20-2
description 20-1 to 20-2
exceptions and errors 20-2
RLEC bit 9-10, 10-10
RSmk (Report Setmarks) bit 9-15, 10-14
S
SCSI
bus reset 2-12
command descriptor block 1-5 to 1-7
command format 1-4 to 1-7
command format errors 1-7
command status 1-8 to 1-9
control byte format 1-5
operation code format 1-5
standards 4-xiv
supported commands 1-2 to 1-3
Self Test diagnostic page 16-3, 21-4
SEND DIAGNOSTIC (1Dh) command
I-6
SCSI REFERENCE
description 21-1
Diagnostic Parameter Header 21-3
diagnostic tests 21-3 to 21-4
field definitions 21-2 to 21-3
Self Test page (F0h) 21-4
Supported Diagnostic Pages page
(00h) 21-4
sense keys, definitions 18-4 to 18-5
serial number of tape drive 4-8
service, returning the tape drive 1-ii
setmarks
description 2-4
detected during read 12-4
detected during space 22-4
legal tape positions for writing 26-1
RSmk bit 9-15, 10-14
spacing over 22-2
writing with WRITE FILEMARKS 26-2
SILI (Suppress Illegal Length Indication)
bit 12-2
SPACE (11h) command
description 22-1 to 22-2
exceptions and errors 22-3 to 22-7
field definitions 22-2 to 22-3
supported operations 22-2
Standard Inquiry Data 4-3 to 4-6
standards, related 4-xiv
start/pause operation 2-5
status of commands 1-8 to 1-9
streaming operation 2-5
Supported Diagnostic Pages page
RECEIVE DIAGNOSTIC RESULTS 16-3
SEND DIAGNOSTIC 21-4
Supported Log Pages page 8-8
supported media types, MODE SENSE Medium
Type 10-4
Supported Vital Product Data page 4-6 to 4-7
T
Tandberg Data, contacting 1-ii
tape
See cartridges
Tape Capacity page, LOG SENSE parameter
codes 8-13
tape drive
device drivers 1-10
implementing operations 2-1 to 2-13
1013599
INDEX
physical path communications 1-1
resetting 2-11 to 2-13
serial number 4-8
status 1-8 to 1-9
Tape Last FSC page, LOG SENSE parameter
codes 8-16 to 8-18
tape positions
for appending data 24-1
for appending filemarks 26-1
for appending setmarks 26-1
Tape Usage page
description 8-14
LOG SENSE parameter codes 8-15 to 8-16
TapeAlert page
description 8-9 to 8-12
LOG SENSE parameter codes 8-10 to 8-12
MODE SELECT command 9-22 to 9-24
MODE SENSE command 10-17 to 10-20
TEST UNIT READY (00h) command
description 23-1
exceptions and errors 23-2
field definitions 23-1
transfer length incorrect, read operation 12-3
U
unbuffered write operation 24-2
Unit Attention (6h) sense key
clearing 2-10
conditions causing 2-9
effect of changing data cartridges 2-10
Unit Attention (6h) sense key, definition 18-5
unit sense bytes 18-8
Unit Serial Number page 4-8
unloading a data cartridge 2-2 to 2-3
unrecoverable error
during read 12-6
during space operation 22-6
during write 24-4, 26-4
Vendor Unique Parameters Page 2, MODE
SENSE 10-24
Volume Overflow (Dh) sense key,
definition 18-5
VXA-2 differences from VXA-1 1-10
W
WRITE (0Ah) command
buffered and unbuffered modes 24-2
description 24-1 to 24-2
exceptions and errors 24-3 to 24-6
field definitions 24-3
legal tape positions 24-1
specifying fixed-length or variable-length
block writes 24-3
WRITE BUFFER (3Bh) command
aborting 25-2
description 25-1 to 25-2
differences between VXA-1 and VXA-2 1-10
exceptions and errors 25-5
field definitions 25-2 to 25-3
parameter list length 25-3
precautions when using 25-2
using to update microcode 25-3 to 25-4
Write Error Counters
LOG SELECT parameter codes 7-6
LOG SENSE parameter codes 8-8
WRITE FILEMARKS (10h) command
description 26-1
exceptions and errors 26-3 to 26-5
field definitions 26-2
legal tape positions 26-1
writing setmarks 26-2
write-protect switch
effect on WRITE 24-6
effect on WRITE FILEMARKS 3-3, 26-5
WSmk (Write Setmark) field 26-2
V
variable-length logical blocks
block length 9-5, 10-6
specifying for read operations 12-2
specifying for write operations 24-3
Vendor Unique Parameters Page 1
MODE SELECT command 9-24 to 9-28
MODE SENSE 10-20 to 10-23
OCTOBER 2008
VXA-320 TAPE DRIVE
I-7
INDEX
I-8
SCSI REFERENCE
1013599
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