Storage system

Storage system
US006263454B1
(12) United States Patent
(10) Patent N0.:
Gold et al.
(54)
(45) Date of Patent:
STORAGE SYSTEM
Inventors: Stephen Gold; Jonathan Conrad
Lord; Philip John Turner, an of
5,500,940
Bristol (GB)
5,757,594 * 5/1998 Dang et a1.
(73) Assignee: Hewlett-Packard Company, Palo Alto,
CA (US)
Notice:
Kubo ............................. .. 395/182.02
5,463,765 * 10/1995 Kakuta 6t a1~
*
5,764,881
(*)
Jul. 17, 2001
5,455,926 * 10/1995 Keele et a1. ........................... .. 711/4
5,463,763 * 10/1995
(75)
US 6,263,454 B1
3/1996
*
395/182-04
Skeie . . . . . . . . . . . .
. . . . . .. 714/25
360/191
6/1998
Yoshida ......................... .. 395/182.06
5,844,919 * 12/1998
Glover et a1. ...................... .. 714/769
OTHER PUBLICATIONS
Subject to any disclaimer, the term of this
patent is extended or adjusted under 35
IBM TDB, vol. 37, No. 02B, Feb. 1994, p 241, “Keeping
U.S.C. 154(b) by 0 days.
Program”.
Users AWare of the Status of an Object Affected by Multiple
IBM TDB, vol. 37, No. 06B, Jun. 1994, pp 499—501,
Operating Intervention Message Management for Tape
Drive Displays.
European Search Report; EP 96305388.
* Cited by examiner
(21) Appl. N0.: 08/888,716
(22) Flled:
(30)
Jul‘ 7’ 1997
Foreign Application Priority Data
Jul. 23, 1996
(EP) ............................................... .. 96305388
Primary Examiner—Thomas Lee
Assistant Examiner_Nguyen Xuan Nguyen
(52)
Int. (:1-7 .................................................... ..
US. Cl. ................................ .. 714/25; 714/30; 714/46
(58)
Field of Search ............................. .. 395/800, 182.06,
(57)
395/182~04> 182-02; 235/153; 360/191;
371/13> 24; 364/900; 714/25> 30> 46
The present invention relates to storage systems for com
puter data and relates particularly to diagnosis of errors and
_
(56)
ABSTRACT
status monitoring of such a system. The invention provides
References Clted
a system for storing computer data in Which different error
U_S_ PATENT DOCUMENTS
messages are generated according to hoW many times a
speci?ed loW-level error has occurred. In the particular
4,048,481 *
9/1977 Bailey, Jr. et a1. ................ .. 235/153
470537752 * 10/1977 DeJ°_hn et a1‘
4,549,295
10/1985
Purvis
714/710
...............
4,689,767 *
8/1987 Stevenson et a1.
5,200,960
4/1993
5,450,609
*
Hamilton
embodiment, different combinations of error messages are
. . . . ..
generated according to hoW many times a particular loW
371/13
level error has occurred'
364/900
.......
. . . . ..
371/24
9/1995 Schultz et a1. ..................... .. 395/800
HOST COMPUTER
16 Claims, 2 Drawing Sheets
[31
/12
MAIN MEMORY
36
35
BACKUP soFIwARE
3
(
CENTRAL
f 7
[32
NET
OPERATING SYSTEM
[34
SCSI
/L\I_Z> PROCESSING
/33
(38
UNIT
DISPLAY
DISPLAY
/\
/ 1o
39
TO
NETWORK
TAPE DRIVE CONTROLLER
J [21
LOW LEvEL FLAG INTERPRETER
STATUS CODE AND HIGH LEVEL
MONITOR AND
FLAG
,4 GENERATOR
HOST
242
STATUS/ERROR
CODE
GENERATOR
244
HIGH LEVEL
CODE
/
(29
DECK
K2
DATA FORMATTER
295
24
(HIGH LEVEL CODE STORE)
25
/
0
MEMORY
/
TAPE DRIVE
24s
PRIoRrnzER~
FIRMWARE
INTERFACE
[23
_._~___>I
TAPE
U.S. Patent
Jul. 17, 2001
Sheet 1 0f 2
US 6,263,454 B1
US 6,263,454 B1
1
2
STORAGE SYSTEM
error conditions is communicated according to hoW many
TECHNICAL FIELD
occurred.
Thus, in the embodiments to be described, the loW-level
errors are grouped into broad categories. If successive errors
Within one of these groups occur, this triggers different
combinations of the high level error conditions.
times a loW-level error of the same functional type has
The present invention relates to devices for storing com
puter data and relates particularly to diagnostics and status
monitoring.
In the embodiments to be described, the system comprises
BACKGROUND ART
It is knoWn to provide status monitoring in a disc drive
and US. Pat. No. 5,450,609 describes one such system in
Which an array of disc drives includes a facility for status
monitoring and for Warning the user of a problem. The
Warning facility described is not very different in scope from
the knoWn facility on existing tape drives of a Warning light
indicating failure of a backup operation.
means for communicating different high level error condi
10
running a cleaning cycle and so, in practice, this is often the
?rst suggested error recovery step.
Preferably, the error messages are categorised according
15
to severity. In the embodiments to be described there are
three categories of severity: Information, Warning and Criti
cal.
The system may comprise means automatically to initiate
a predetermined sequence of error recovery steps according
to the high level error conditions identi?ed. This feature
DISCLOSURE OF INVENTION
The present invention aims to provide a status monitoring
and diagnostic facility for a storage device Which takes
account of the fact that the storage medium is removable and
Which diagnoses a Wider set of error conditions than simply
?agging imminent failure and Which also takes account of
the number of occurrences of a particular type of error.
According to the present invention We provide a system
tions according to the elapsed time since the storage device
Was last cleaned. Many error conditions can be alleviated by
means that some error recovery or error prevention steps
may automatically be initiated by the controller rather than
the user. One possibility in the case of an autoloader (a
25
for storing computer data comprising:
system With a mechanism for automatically loading media
into a storage device), Would be an automatic cleaning cycle
using specialised cleaning media.
Preferably, error status information is stored in the storage
device in a standardised format. This feature enables backup
softWare applications to interface With storage devices from
a storage device having means for reading data from and
Writing data to removable media;
different manufacturers Which implement the present inven
tion. In this Way, the invention provides a technique Whereby
and a controller,
Wherein the storage device comprises:
the Way in Which errors are detected and categorised for a
means to perform error diagnosis and to translate loW
level error indicators into a plurality of high level error
particular storage device is device-speci?c and can be
decided by the device manufacturer but Within the conteXt of
conditions;
means to communicate occurrence of these high level 35 a standardised scheme Which enables all devices complying
With the standardised format to interface With backup appli
cation softWare from different softWare providers in order to
error conditions to the controller to trigger the provision of
error messages to the user;
provide the user With consistent error indications.
There are different Ways in Which the controller may
receive error information from the storage device. In one
means for communicating different high level error con
ditions according to hoW many times a speci?ed loW-level
error has occurred.
embodiment to be described, the system is con?gured so that
Thus, in systems implementing the present invention, the
particular high level error conditions communicated depend
the occurrence of high level error conditions is communi
on hoW many times a relevant loW-level error has occurred.
This feature enables the provision of a succession of differ
ent error messages to the user recommending different
actions if an error persists.
The term ‘loW-level error indicator’ is intended to cover
45
error conditions is communicated to the controller Whenever
a neW error is indicated by the storage device.
In the embodiments to be described, the storage device is
a tape drive, but the invention applies also to other storage
devices With removable media eg. optical disc drives.
The controller may be backup controller softWare running
on a host computer. Alternatively the system may be part of
netWork in Which the controller is backup softWare running
both error codes and other relevant triggers generated in the
storage device. LoW-level error codes cover items such as
unrecoverable read and/or Write errors but there are also
other relevant triggers for high level error conditions such as
the rate at Which data is being Written, data relevant to the
media being used etc. LoW-level error indicators are nor
mally generated by the ?rmWare in the storage device.
on a backup server on the netWork. HoWever, the invention
55
The system may be con?gured so that only one high level
error condition is communicated as a result of the occur
rence of a loW-level error indicator. HoWever, very often
the occurrence of a loW-level error so that the user may
receive a corresponding combination of error messages. In
Other aspects and features of the present invention Will
the embodiments to be described, the system comprises
means for communicating different combinations of high
become apparent from the folloWing description, claims and
draWings.
level error conditions according to hoW many times a
functional types and a predetermined sequence of high level
is not limited to these alternatives and the controller may be
implemented in softWare and/or hardWare and may be in a
general purpose computer or a dedicated device, Whether
standalone or connected to a netWork. The system may
comprise a plurality of storage devices such as in an auto
loader or a coordinated array of storage devices.
more than one high level error condition may be triggered by
particular loW-level error has occurred.
Preferably, the loW-level error indicators are grouped into
cated to the controller at predetermined points in a storage
operation. In another embodiment to be described, the
system is con?gured so that the occurrence of high level
65
BRIEF DESCRIPTION OF DRAWINGS
Particular embodiments of the present invention Will noW
be described, by Way of eXample, With reference to:
US 6,263,454 B1
4
3
mined functions in the tape drive 10 by receiving loW level
system status codes returned by the other elements of the
drive during the operation of the tape drive and, in response,
sets ?ags to indicate possible problems; a second process
244 interprets the ?ags in a predetermined manner and
FIG. 1 Which shows a tape drive connected to a host
computer; and
FIG. 2 Which shows by Way of a functional block diagram
the system of FIG. 1.
The invention Will also be described, by Way of example,
generates one or more predetermined high level status or
With reference to tables reproduced at the end of this
error codes; and a third process 246 prioritiZes the high level
codes, Where more than one code eXists, in accordance With
description in Which:
Table 1 shoWs the error conditions relating to particular
a pre-de?ned criteria and stores the results in an area of
?ags;
random access memory (RAM) 25 accessible by the tape
drive controller 23. Once stored, the high level codes may be
forWarded to the host computer 12, for eXample by
Table 2 shoWs the sequences of error conditions for
read-after-Write errors;
Table 3 shoWs the sequences of error conditions for read
“polling”, as described beloW in more detail. The loW level
codes, the ?ags, the high level codes and the priority criteria
errors;
Table 4 shoWs the sequences of error conditions for hard 15 are also described in detail beloW.
As also illustrated in FIG. 2, the host computer 12
errors;
comprises a standard computing platform running under the
Table 6 shoWs the format of the Log Sense page;
Table 6 shoWs the format of the Mode Sense page.
control of an operating system 37 such as WindoWs NT 4.0.
Backup controller softWare 36, stored in main memory 31
BEST MODE FOR CARRYING OUT THE
and running on a central processing unit 35, is a softWare
INVENTION, & INDUSTRIAL APPLICABILITY
process Written, for example, in the C++ programming
language. The backup softWare 36 is arranged to control the
Referring to FIG. 1, a tape drive 10 is directly connected
to a host computer 12. The tape drive 10 receives data to be
backed up from the host computer 12 and sends saved data
back to the host When requested. A standard SCSI (‘Small
Computer System Interface’) interface is used to intercon
nect the tape drive 10 With the host computer 12.
FIG. 2 is a functional block diagram of the system
represented in FIG. 1. In FIG. 2, the tape drive 10 is arranged
to store and retrieve data in accordance With the digital data
25
host computer 12 to operate in accordance With the present
embodiment. The operating system 37 of the host computer
12 includes: a netWork driver 32 for transmitting and receiv
ing data, for eXample in TCP/IP format, to and from a
netWork (not shoWn); a display driver 33, such as a video
graphics array (VGA) driver, to transmit display signals to
a display screen 38; and a SCSI driver 34, to transfer
commands and data betWeen the host computer 12 and the
tape drive 10. The drivers provided support respective
storage (DDS) standard format. The tape drive 10 comprises
standard hardWare interfaces.
a host interface unit 21 for interfacing the drive 10 With a
host computer 12 via a standard SCSI bus 39. A data
formatter 22 in the tape drive 10 processes user data records
and separator marks into and out of indeXed groups,
compresses/decompresses data in a knoWn fashion and
the host computer 12 to retrieve high level status or error
35 codes Which have been stored in the memory 25 from the
effects loW-level signal processing, as speci?ed in the DDS
format. The loW-level processing converts streams of bytes
from the groups into track signals ready for recording data
to tape and reconverts track signals from tape back into byte
streams for reconstructing the groups. The tape drive 10
further comprises a deck 29 of knoWn type comprising
high level status or error codes and forWard to a user
The backup controller softWare 36 is arranged to control
tape drive 10 by polling the tape drive 10 regularly. Other
methods of moving the data from the tape drive 10 to the
host computer 12 are described beloW. Further, the backup
controller softWare 36 is arranged to process any received
appropriate, pre-de?ned error or action messages. Such
messages may be forWarded for display to the user on the
display screen 38, and/or across a netWork to a remote
electronic circuitry for controlling recording heads and tape
operations for Writing data to and reading data from a tape
medium 295. The tape drive 10 also comprises a tape drive
controller 23 for controlling the operation of the other
45
elements of the drive in response to commands received
from the host 12 via the host interface unit 21.
problems—these are referred to herein as ‘loW-level’ error
codes. For any given tape drive, these loW-level error codes
The drive 10, controlled by the tape drive controller 23, is
arranged to respond to SCSI commands from backup soft
are mapped to ‘high level’ error conditions so that occur
rence of a loW-level error condition causes a particular ?ag
Ware 36 running the host computer 12 to load/unload a tape,
or ?ags to be set. The speci?c conditions for any one ?ag to
be set and cleared are drive-speci?c and are de?ned by the
drive manufacturer. If a drive cannot support the recognition
to store a data record or separator mark, to search for
selected separator marks or records, and to read back the
neXt record and to compress/decompress data records. These
functions are standard tape drive functions and, as such, Will
not be considered in further detail in this description. For
further, more detailed information on DDS tape drives and
55
of all the ?ag conditions, then unsupported ?ags may remain
unset.
LoW-level error indicators may be grouped into functional
types With a set of possible loW-level error indicator codes
the respective data format, the reader is referred to European
Patent Application EP459041A1.
In accordance With the present embodiment, the tape
drive controller 23 incorporates further functionality, Which
being assigned to each group. The relevant functional types
include:
Unrecoverable Write error codes;
Unrecoverable read error codes;
a storage device has hitherto not provided, to support status
monitoring and tape drive diagnostics capabilities. This
functionality is provided by appropriate ?rmWare processes
netWork console (not shoWn) as necessary.
As mentioned above, the tape drive 10 ?rmWare 24
monitors the status of predetermined functions in the drive
and is con?gured to generate error codes to indicate possible
Tape management error codes;
24 embedded in the tape drive controller 23. Of the pro
HardWare error codes;
Recoverable Write error codes;
cesses: a ?rst process 242 monitors the status of predeter
Recoverable read error codes.
65
US 6,263,454 B1
5
6
There are also other groups in addition to the above in this
embodiment as Will be shoWn later.
since the tape drive Was last cleaned, the de?ned state
toggles betWeen 1,2 and 3 as hard errors Within the three
categories reoccur. The events Which trigger state changes
If such grouping is done, then ?ags may be set according
are listed at the bottom of Table 4 as folloWs:
to Which type of loW-level error indicator has occurred. For
example, all recoverable Write error codes Would cause a
Cln—performance of a cleaning cycle;
particular ?ag to be set, in fact Flag 1 in Table 1 in this
embodiment. This feature relieves the tape drive manufac
Md Ej—ejection of the current tape cassette;
Soft Reset—performing a soft reboot;
Hard Reset—poWering the tape drive off and on again.
turer of the need to de?ne a mapping from every single
loW-level error indicator to a particular ?ag. This feature
also facilitates the setting of different ?ags depending on
For hard read errors (Which include certain media-related
10
errors):
hoW many times a particular type of loW-level error has
occurred.
State 1 means that ?ags 3 and 20 are set;
State 2 means that ?ags 3 and 4 are set;
State 3 means that ?ags 3 and 5 are set.
There are 64 ?ags de?ned to cover a Wide range of error
conditions and these are as shoWn in Table 1. The column
headings in Table 1 are as folloWs:
15
For hard Write errors:
No.—this is simply the ?ag number;
State 1 means that ?ags 3 and 20 are set;
State 2 means that ?ags 3 and 4 are set;
State 3 means that ?ags 3 and 6 are set.
Flag—this is the name of the ?ag and indicates the error
to Which it relates;
Type—this indicates the seriousness of the error:
For hardWare errors:
“I”=Information: a suggestion to the user;
“W”=Warning: the user is advised to take action. Perfor
mance or data may be at risk;
“C”=Critical!: action should be taken immediately;
Suggested Host Message—this is the teXt of the message
Which should be relayed to the user eg. by display on the
State 1 means that ?ags 3 and 30 are set;
Subsequent States means that ?ags 3 and 31 are set.
Alternatively, it may be that soft resets are not a recom
25 mended error recovery step, in Which case a hardWare error
code means that ?ags 3 and 30 Will alWays be set indepen
dently of hoW many times a hardWare error has occurred.
It can be seen from Tables 2,3 and 4 above that the elapsed
time since the tape drive Was last cleaned is relevant to the
de?ned state Which in turn in?uences Which ?ags are set.
screen of the host computer;
Cause—this indicates the cause of the error. Where setting
of a ?ag depends on a simple true/false criterion, the cause
is given in Table 1. Where setting of a ?ag depends on the
number of times a particular type of error occurs in a
The folloWing is a description of different possible error
scenarios and the error messages that Would result, including
predetermined timeframe, details are given in Tables 2 to 4
(to be described).
If a ?ag Will be set repeatedly on repeated triggering of the
speci?ed cause, this is indicated by ‘R’. If a ?ag Will not be
set repeatedly on repeated triggering of the speci?ed cause,
this is indicated by ‘NR’.
Cleared—this indicates When the ?ag is cleared.
The ?ags are grouped as folloWs:
Flags 1 to 19: For tape drive Write/read management
Flags 20 to 29: For cleaning management
Flags 30 to 39: For tape drive hardWare errors
Flags 40 to 49: For tape autoloader errors
Flags 50 to 64: Currently unassigned for future use
references to the relevant ones of Tables 1 to 4 in each case.
35
These scenarios correspond closely to the functional types of
loW-level errors mentioned above.
There is a ‘caution’ LED on the tape drive 10 (not shoWn
in FIG. 1) Which is normally lit if there is a problem.
1. DRIVE RECOVERABLE READ PROBLEMS (Table
3)
If the tape drive experiences a severe problem reading,
then the yelloW caution LED is lit. Data is still read from the
tape Without error, but With loss of capacity. The recom
mended recovery procedure is to try cleaning the tape drive,
45
then to try a different piece of media, and ?nally if the
problem persists to seek technical support.
Table 2 shoWs the combinations and sequences of error
conditions for read-after-Write errors. When it is more than
The ?rst time the error is detected, the folloWing error
messages Would be displayed:
24 hours since the tape drive Was last cleaned (State 1), ?ags
WARNING: The tape drive is having problems reading
2 and 20 are set on occurrence of a read-after-Write (RAW)
data. No data has been lost, but there has been a reduction
error. When it is less than 24 hours since the tape drive Was
in the capacity of the tape.
last cleaned (State 2), ?ags 2 and 4 are set on occurrence of
a read-after-Write (RAW) error.
CRITICAL: The tape drive needs cleaning:
Table 3 shoWs the combinations and sequences of error
1. If the operation has stopped, eject the tape and clean the
conditions for read errors. When it is more than 24 hours 55 drive
since the tape drive Was last cleaned, the tape drive is in
2. If the operation has not stopped, continue and clean the
drive When ?nished.
State 1 and ?ags 1 and 20 are set on occurrence of a
recoverable read error. If it is less than 24 hours since the
If the error persists, then the neXt set of error messages to
tape drive Was last cleaned, the de?ned state toggles betWeen
be displayed is:
WARNING: The tape drive is having problems reading
1 and 2 as recoverable read errors reoccur. In State 2 ?ags
1 and 4 are set on occurrence of a read error.
data. No data has been lost, but there has been a reduction
Table 4 shoWs the combinations and sequences of error
in the capacity of the tape.
conditions for unrecoverable (or ‘hard’) errors. Unrecover
CRITICAL: Your data is at risk:
able errors fall into three groups: bard read errors, hard Write
errors and hardWare errors.
When it is more than 24 hours since the tape drive Was last
cleaned, the tape drive is in State 1. If it is less than 24 hours
65
1. Copy any data you require from this tape.
2. Do not use this tape again.
3. Restart the operation With a different tape.
US 6,263,454 B1
8
7
CRITICAL: The tape is damaged or the drive is faulty.
This cycle repeats each time the error condition is
detected again.
Call the tape supplier helpline.
4. DRIVE UNRECOVERABLE PROBLEMS (Table 4)
2. DRIVE RECOVERABLE WRITE PROBLEMS
(Table 2)
If the tape drive experiences a severe problem Writing,
then the yelloW caution LED is lit. Data is still Written to the
tape Without error, but With loss of capacity. The recom
mended recovery procedure is to try cleaning the drive, then
to try a different piece of media, and ?nally if the problem
persists to seek technical support.
If the tape drive experiences an unrecoverable Write
failure, then the yelloW caution LED is lit and the user’s
backup job fails. The recommended recovery procedure is to
try cleaning the drive, then to try a different piece of media,
and if the problem persists, to seek technical support. The
?rst time the error is detected the folloWing error messages
10
WARNING: The operation has stopped because an error
The ?rst time the error is detected, the following error
has occurred While reading or Writing data Which the tape
messages Would be displayed:
drive cannot correct
WARNING: The tape drive is having problems Writing
data. No data has been lost, but there has been a reduction
Would be displayed:
15
in the capacity of the tape.
CRITICAL: The tape drive needs cleaning:
1. If the operation has stopped, eject the tape and clean the
CRITICAL: The tape drive needs cleaning:
1. If the operation has stopped, eject the tape and clean the
drive
2. If the operation has not stopped, continue and clean the
drive When ?nished.
drive
2. If the operation has not stopped, continue and clean the
drive When ?nished.
If the error persists, then the same set of error messages
is displayed again:
If the error persists, then the next set of error messages to
WARNING: The operation has stopped because an error
be displayed is:
WARNING: The tape drive is having problems Writing
has occurred While reading or Writing data Which the tape
25
data. No data has been lost, but there has been a reduction
drive cannot correct
CRITICAL: Your data is at risk:
in the capacity of the tape.
1. Copy any data you require from this tape.
CRITICAL: Your data is at risk:
2. Do not use this tape again.
3. Restart the operation With a different tape.
1. Copy any data you require from this tape.
2. Do not use this tape again.
3. Restart the operation With a different tape.
This cycle repeats each time the error condition is
If the error persists, then the next set of error messages to
be displayed is:
WARNING: The operation has stopped because an error
has occurred While reading or Writing data Which the tape
detected again.
3. DRIVE UNRECOVERABLE READ PROBLEMS 35 drive cannot correct
CRITICAL: The tape is from a faulty batch or the tape
(Table 4)
drive is faulty:
If the tape drive experiences an unrecoverable read
failure, then the yelloW caution LED is lit and the user’s
backup job fails. The recommended recovery procedure is to
try cleaning the tape drive, then to try a different piece of
media, and if the problem persists, to seek technical support.
1. Use a good tape to test the drive.
2. If the problem persists, call the tape drive supplier
helpline.
5. DRIVE HARDWARE PROBLEMS (Table 4)
The ?rst time the error is detected, the folloWing error
messages Would be displayed:
WARNING: The operation has stopped because an error
has occurred While reading or Writing data Which the tape
45
drive cannot correct
try ‘poWer cycling’ the drive (turning the tape drive off and
then on again). Finally, if the problem persists, technical
CRITICAL: The tape drive needs cleaning:
1. If the operation has stopped, eject the tape and clean the
support should be sought. The folloWing error message
Would be displayed:
drive
2. If the operation has not stopped, continue and clean the
drive When ?nished.
CRITICAL: The tape drive has a hardWare fault:
1. Turn the tape drive off and then on again.
If the error persists, then the next set of error messages to
2. Restart the operation.
be displayed is:
WARNING: The operation has stopped because an error
has occurred While reading or Writ data Which the tape drive
55
CRITICAL: Your data is at risk:
data on it should be copied to neW media and the old media
discarded. There is normally no user visibility of media
Wear, and thus the media Will continue being used until it
triggers one of the read/Write error conditions. The folloWing
error message Would be displayed:
1. Copy any data you require from this tape.
2. Do not use this tape again.
3. Restart the operation With a different tape.
If the error persists, then the next set of error messages to
be displayed is:
has occurred While reading or Writing data Which the tape
drive cannot correct
3. If problem persists, call the tape drive supplier helpline.
6. MEDIA WORN OUT (Table 1)
When the media being used has reached the end of its
useful life (maximum number of passes exceeded) then the
cannot correct
WARNING: The operation has stopped because an error
If the tape drive experiences a hardWare self-test failure
after poWer-on, then the yelloW caution LED is lit and the
backup controller softWare Will report that the tape drive
cannot be used. The recommended recovery procedure is to
65
WARNING: The tape cartridge has reached the end of its
useful life:
1. Copy any data you need to another tape
2. Discard the old tape.
US 6,263,454 B1
9
10
tape drive. The folloWing error message Would explain Why
the cartridge Was ejected:
7. CLEANING TAPE EXPIRED (Table 1)
When the cleaning tape being used Wears out, it should be
discarded and a neW cleaning tape used if possible. Unless
the user is made aWare of the problem, the Worn cleaning
INFORMATION: You have tried to load a cartridge of a
type Which is not supported by this drive.
tape might Well continue being used until it triggers one of
the read/Write error conditions. To alert the user the folloW
The cartridge has been automatically ejected
12. FIRMWARE DOWNLOAD FAILURE (Table 1)
ing error message Would be displayed:
CRITICAL: The last cleaning cartridge used in the tape
the tape drive, the doWnload Will not succeed. The folloWing
If an attempt is made to doWnload incorrect ?rmWare into
drive has Worn out:
1. Discard the Worn out cleaning cartridge.
2. Wait for the current operation to ?nish.
10
3. Then use a neW cleaning cartridge.
8. PERIODIC CLEANING REQUIRED (Table 1)
When the tape drive is due for periodic cleaning, a
cleaning cycle should be performed. Unless the user is made
aWare of the need for a cleaning cycle, the tape drive might
Well continue being used until lack of cleaning triggers one
15
ERROR (Table 1)
In the case of an autoloader, if there is a problem With the
tape autoloader Where the tape drive cannot communicate
correctly With the changer mechanism, the autoloader Will
not function correctly, and the backup operation fails. The
recommended recovery procedure is to try poWering the tape
drive off then on again, and ?nally if the problem persists to
of the read/Write error conditions. To alert the user, the
folloWing error message Would be displayed:
WARNING: The tape drive is due for routine cleaning:
1. Wait for the current operation to ?nish.
seek technical support. The folloWing error messages Would
2. Then use a cleaning cartridge.
9. NON-DATA GRADE MEDIA USED (Table 1)
When the media being used is not data grade, the data
error message noti?es the user that the ?rmWare doWnload
failed:
WARNING: The ?rmWare doWnload has failed because
you have tried to use the incorrect ?rmWare for this tape
drive.Obtain the correct ?rmWare and try again.
13. AUTOLOADER HARDWARE INTERFACE
25
be displayed:
CRITICAL: The changer mechanism is having dif?culty
communicating With the tape drive:
stored on it is at risk. Unless the user is made aWare of the
1. Turn the autoloader off and then on again.
problem, the media might Well continue being used until it
2. Restart the operation.
3. If the problem persists, call the tape drive supplier
triggers one of the read/Write error conditions. The user
should copy any data they need from the media onto data
helpline.
grade media and discard the non-data grade media. To alert
14. AUTOLOADER STRAY TAPE (Table 1)
the user the folloWing error message Would be displayed:
In the case of an autoloader, it is possible for a tape to be
left inside the autoloader after an error, preventing the
WARNING: The tape cartridge is not data-grade. Any
data you back up to the tape is at risk.
Replace the cartridge With a data-grade tape.
10. ABNORMAL ERROR CONDITIONS (Table 1)
autoloader from functioning correctly, and the user’s backup
operation Will fail. The recommended recovery procedure is
to try inserting an empty magaZine into the autoloader, then
If an abnormal error condition occurs, due to user or
if the backup operation is still failing, poWering the tape
backup application error, then in knoWn systems there Will
be unexplained failures. One example is if the backup
seek technical support. The folloWing error message Would
35
drive off then on again, and ?nally if the problem persists to
be displayed:
controller softWare fails to note that the cartridge loaded is
CRITICAL: A tape has been left in the autoloader by a
Write protected and thus fails the backup operation. In a
previous hardWare fault:
system implementing the present invention, the folloWing
error message Would explain this:
CRITICAL: You are trying to Write to a Write-protected
45
cartridge.
3. If the problem persists, call the tape drive supplier
Remove the Write-protection or use another tape.
helpline.
Another example is if the user tries to eject the cartridge
When it has been locked in the drive by the backup controller
softWare. The folloWing error message Would explain Why
the cartridge Was not ejected:
INFORMATION: You cannot eject the cartridge because
15. AUTOLOADER MECHANISM HARDWARE
ERROR (Table 4, if applicable)
In the case of an autoloader, if there is a problem With the
tape autoloader mechanism/robotics, the autoloader Will not
the tape drive is in use.
Wait until the operation is complete before ejecting the
1. Insert an empty magaZine to clear the fault.
2. If the fault does not clear, turn the autoloader off and
then on again.
55
cartridge.
function correctly, and the user’s backup operation fails. The
recommended recovery procedure is to try ejecting the
magaZine, then to try a soft reset (holding doWn the eject
button for several seconds Without a tape loaded in the
Also, in the case of an autoloader, the cleaning cartridge
drive), then to try poWering the tape drive off then on again,
and ?nally if the problem persists to seek technical support.
may be used in error for a backup or restore, thus causing
unexplained failures. The folloWing error message Would
The ?rst time the error is detected the folloWing error
explain this:
messages Would be displayed:
INFORMATION: The tape in the drive is a cleaning
WARNING: There is a problem With the autoloader
mechanism.
cartridge.
If you Want to back up or restore, insert a data-grade tape.
11. UNSUPPORTED TAPE FORMAT (Table 1)
If a tape cartridge is loaded in the tape drive that is an
unsupported format, it Will be automatically ejected by the
65
CRITICAL:The operation has failed:
1. Eject the tape or magaZine.
2. Insert the tape or magaZine again.
3. Restart the operation.
US 6,263,454 B1
11
12
If the problem is detected again, then the following error
DU=Disable Update: a value of Zero means that the tape
drive Will not update the log parameter value (Entry 8
messages are displayed:
WARNING: There is a problem With the autoloader
mechanism.
CRITICAL:The tape drive has a hardWare fault:
1. Eject the tape or magaZine
2. Reset the drive (hold eject button doWn for 5 seconds).
3. Restart the operation.
If the problem is detected again, then the folloWing error
messages are displayed:
WARNING: There is a problem With the autoloader
mechanism.
CRITICAL:The tape drive has a hardWare fault:
1. Turn the tape drive off and then on again.
beloW). A value of one means that the tape drive Will not
update the log parameter value eXcept in response to a Log
Select command that speci?es a neW value for the log
parameter. The DU bit is unde?ned and ignored if the PC bit
(part of the page code) in the Log Sense command is set to
0x00 (as in this embodiment);
DS=Disable Save: a value of Zero means that the tape
1O
means means that saveable parameters are not supported;
TSD=Tape drive Save Disable: a value of Zero means that
15
ETC=Enable threshold comparison: a value of one means
that comparison to the threshold value is performed. Avalue
helpline.
of Zero means that a comparison is not performed;
TMC=Threshold Met Criteria: de?nes the basis for the
16. AUTOLOADER DOOR OPEN (Table 1)
comparison of the parameter value. Only valid if ETC=1. If
In the case of an autoloader, if the door of the autoloader
the ETC=1 and the comparison is true, a check condition
Will be generated. The Sense key is then set to UNIT
ATTENTION and the additional sense code is set to
25
parameter, and then the ETC and TMC ?eld must be set to
Zero;
Entry 7—the length of the current parameter;
Entry 8—the actual parameter. In this case it is the ?rst
2. Eject the magazine and then insert it again.
35
4. If the problem persists, call the tape drive supplier
helpline.
drive 10. The ?rst method is “polling” Where the Log Sense
page is read from the tape drive at the folloWing times as a
minimum:
1. Immediately after a SCSI Check Condition/Request
Sense cycle. This is a standard cycle in Which the drive
45
The error information contained in Table 1 is stored by the
tape drive 10 in a ‘Log Sense’ page. The format of the Log
Sense page is shoWn in Table 5. Each line in the Log Sense
page represents one byte of data and the entries are num
bered doWn the lefthand side of Table 5. A description of the
The second access method is to use the SCSI ‘Mode
55
Select’ command to enable the “Check Condition” mode, so
that the tape drive Will report a Check Condition on the neXt
SCSI a command after one or more ?ags are set. If this SCSI
command should return a Check Condition due to an actual
Entry 3—the remainder of the page length;
Entry 4—the SCSI standard uses parameters and this is
error, then this Will override the Check Condition ‘forced’ by
the Mode Select command. The Log Sense page Will there
fore be read from the tape drive after every Check
the name of the current parameter (2 bytes long). In this
embodiment, each parameter corresponds to one of the ?ags
in Table 1;
Entry 5—the remainder of the parameter name;
Entry 6—the parameter control byte. The ?elds are
tively:
‘Request Sense’ command to get details of the error.
Sense page must be read before ejection.
3. At the end of a backup/restore job.
It is also recommended to poll the Log Sense page every
60 seconds While the tape drive is idle.
Entry 0—the name of the page (2e in this example);
Entry 1—reserved for future use;
eXplained beloW. The terms ‘sense key’ and ‘sense code’ are
commonly used in relation to the SCSI standard to refer to
codes for the type of error and details of the error, respec
makes an error status report and if there is an error this is
indicated as a ‘Check Condition’. The host then sends a
2. At the end of each tape When the backup/restore job
spans multiple tapes. If the tape is to be ejected then the Log
entries is as folloWs:
Entry 2—the length of the particular page (2 bytes long);
?ag, namely the Read Flag. In this embodiment only one bit
is used for each ?ag;
Entry 9 and so on—corresponding entries for the subse
quent parameters (?ags). There are tWo methods by Which
the host computer 12 can access error information in the tape
The Way in Which the backup controller softWare in the
host computer 12 interfaces With the tape drive 10 Will noW
be described.
AWell-knoWn feature of the standard SCSI interface is the
use of ‘log sense’ pages to record peripheral status infor
mation and ‘mode sense’ pages to record functional and
con?guration settings.
THRESHOLD CONDITION MET;
LP=List Parameter: indicates the format of the log param
eter. A value of Zero means that the parameter is a data
counter. A value of one means that the parameter is a list
1. Clear any obstructions.
3. If the fault does not clear, turn the autoloader off and
then on again.
the tape drive provides a tape drive-de?ned method for
saving log parameters. A value of one means that the tape
drive does not provide a tape drive-de?ned method of saving
log parameters;
2. Restart the operation.
3. If the problem persists, call the tape drive supplier
has not closed correctly after loading a magaZine, then the
autoloader Will not function and the backup operation fails.
The, recommended recovery procedure is to try closing the
door of the autoloader, then if the backup operation is still
failing, poWering the tape drive off then on again, and ?nally
if the problem persists to seek technical support. The fol
loWing error message Would be displayed
CRITICAL: The operation has failed because the auto
loader door is open:
drive supports saving for that log parameter. Avalue of one
Condition/Request Sense cycle (both forced check condi
65
tions and error check conditions). The Request Sense
eXtended sense code (this is the code reported by the tape
drive) for a check condition is 5D00, and the command that
triggered this Check Condition Will have been executed,
thus the backup controller softWare Will not repeat the
command that triggered a Check Condition.
US 6,263,454 B1
14
13
The recommended method is “check condition” rather
than “polling” since this guarantees that the backup control
the sense key set to UNIT ATTENTION and the eXtended
sense code set to 5D00. The command that triggered the
ler softWare Will be made aWare of any ?ag being set. With
“polling” there are theoretical corner-cases Where ?ag infor
forced Check Condition Will not have been executed, and
thus needs to be repeated;
mation could be missed, though the higher the polling
0x3: Conditionally generate Recovered Error: depending
frequency the less chance there is of this happening.
on the value of the tape drive error recovery settings, the tape
The method of access to the tape drive can be con?gured
via the SCSI bus, based on a neW Mode Sense page. The
drive returns Check Condition on the neXt SCSI command
interface can be con?gured via the Mode Select command
using the same page format to Write the con?guration as to
read it (Mode Sense command). The format of this neW
Mode Sense page is as shoWn in Table 6.
RECOVERED ERROR and the eXtended sense code set to
after setting of a ?ag Was detected, With the sense key set to
10
0x4: Unconditionally generate Recovered Error: regard
Again each entry in the Mode Sense page is one byte long.
less of the value of the tape drive error recovery settings, the
The entries are as folloWs:
Entry 0—the name of the page (1C in this example);
15
?eld (so that the backup controller softWare must poll the
Log Sense page). Thus to enable “check condition” mode,
this bit must be set to Zero.
set to RECOVERED ERROR and the eXtended sense code
set to 5D00. The command that has triggered the forced
Check Condition Will have been eXecuted correctly, and thus
does not need to be repeated;
0x5: Generate No Sense: tape drive returns Check Con
dition on the neXt SCSI command after setting of a ?ag Was
detected, With the sense key set to NO SENSE and the
eXtended sense code set to 5D00. The command that has
25
triggered the check condition Will have been eXecuted
correctly, and thus doe; not need to be repeated;
0x6: Only report on request:tape drive Will preserve the
?ag(s) set. The backup controller softWare then polls the
tape drive using the Log Sense command.
In this embodiment, the default setting is 3, not change
In this embodiment, the default setting is 1, and this is
con?gurable via Mode Select
Test: When this bit is set to Zero, this indicates that the
tape drive Will not generate any false ?ags. When this bit is
set to one, the tape drive Will set a false ?ag based on the
MRIE and Interval Timer ?ags. Thus the neXt SCSI com
mand after the Mode Select command Will return Check
Condition, With sense key set to UNIT ATTENTION and
eXtended sense code set to 5DFF (a test code). If both the 35
Test and DEXcpt bits are set to one, then the Mode Select
command Will return Check Condition, With sense key set to
Illegal Request and eXtended sense code set to INVALID
FIELD in the Parameter List.
In this embodiment, the default setting is 0, con?gurable
Report Count: When this ?eld is set to Zero, this indicates
that there is no limit to the number of times the tape drive
When this bit is set to one, the tape drive Will not cause
45
In this embodiment, the default setting is 0, not change
able via Mode Select.
55
Every time the Log Sense page is read from the tape drive,
the backup controller softWare reads all 64 ?ags to discover
Which are set (there is often more than one). There may also
be data associated With a set ?ag in the remainder of the ?ag
byte, Which should also be read. The ?ags Will automatically
be cleared by the tape drive Without action from the
softWare, and thus any set ?ags read by the backup controller
softWare indicate a neW event. The softWare therefore Will
Will report a Check Condition on the neXt SCSI command
after one or more ?ags are set then, in the event that the SCSI
command should return a Check Condition due to an actual
error, then this Will override the forced Check Condition.
The values de?ned for this ?eld are:
OX2: Generate Unit Attention: tape drive returns Check
Condition on the neXt SCSI command after a ?ag is set, With
Will report a ?ag being set (assuming that Interval Timer is
set to non-Zero). When this ?eld is set to non-Zero, this
indicates the number of times to report a ?ag being set.
one described above using the Mode Select command to
enable the “Check Condition” mode, so that the tape drive
OX1: No reporting of ?ags set
able via Mode Select.
Interval Timer. When this ?eld is set to Zero, this indicates
that the tape drive Will only set a ?ag once. When this ?eld
is set to non-Zero, the value indicates the period in 100
millisecond increments for resetting a ?ag. The tape drive
Will not set ?ags more frequently than the speci?ed timer
interval and Will set ?ags as soon as possible after the timer
interval has elapsed. A value of 0><FFFFFFFF in the ?eld
indicates that the timer interval is tape drive speci?c.
In this embodiment, the default setting is 0, not change
able via Mode Select
via Mode Select
Perf: When this bit is set to Zero, this indicates that ?ag
setting operations that can cause delays are acceptable.
delays While setting ?ags (this may cause the tape drive to
disable some or all of the ?ag setting operations).
In this embodiment, the default setting is 0, not change
able via Mode Select
IJogErr: When this bit is set to Zero, this indicates that the
logging of ?ags set Within a tape drive is vendor speci?c.
When this bit is set to one, the tape drive Will log ?ags set.
In this embodiment, the default setting is 0, not change
able via Mode Select
MRIE: This ?eld indicates the method used by the tape
drive to report ?ags set. The priority of reporting ?ags set is
tape drive speci?c. If the access method being used is the
tape drive returns Check Condition on the neXt SCSI com
mand after setting of a ?ag Was detected, With the sense key
Entry 1—the length of the particular page;
The folloWing ?elds are in the remainder of the Mode
Sense page:
DEXcpt: When this bit is set to Zero the reporting method
indicated by the MRIE ?eld is used. When this bit is set to
one this indicates that the tape drive Will ignore the MRIE
5D00. The command that has triggered the forced Check
Condition Will have been eXecuted correctly, and thus does
not need to be repeated;
65
not latch any ?ag states but Will alWays action any set ?ag
detected.
A particular backup controller may be connected to more
than one tape drive. In addition, for each tape drive, there
Will be a plurality of tape cassettes used for backing up data.
Each tape cassette is given a ‘softWare label’ to identify it.
For every ?ag that is set, the backup controller softWare
Will log the error message speci?ed in Table 1 along Wit
details to identify Which tape drive the error refers to, and the
US 6,263,454 B1
15
16
software label of the media for media related actions (?ags
4 and 7). The severity of the error is identi?ed based on the
?ag Type ?eld in Table 1.
For every ?ag that is set, the backup controller softWare
noti?es the user through its normal noti?cation methods
TABLE 1-continued
No Flag
5 Read
C
Failure
(eg broadcast, email, SNMP, etc.), displaying the speci?ed
6 Write
Failure
C
sub
The tape is from a faulty
batch or the tape drive is
1. Use a good tape to test
the drive.
severity (Information/Warning/Critical). It is possible to
15
of different severity. When multiple ?ags are set
simultaneously, they may be associated together as a single
error event, for example by displaying all of the associated
7 Media
Life
exceeded
its
to another tape
speci?ed
8 Not Data
W
Grade
Load of On tape
data-grade. Any data you
Non data eject
back up to the tape is at
risk. Replace the cartridge
With a data-grade tape.
(N/A)
Write
attempt to
Non data
grade
media data
grade
detect
enabled
(R)
9 Write
35
C
Protect
You are trying to Write to a
Write-protected cartridge.
Remove the Write-protection or use another tape.
mini-disk or optical disk (CD ROM. Alternatively, the
10 No
server.
I
Removal
The above embodiment relates to a tape drive but it Will
be understood that the present invention is relevant to any
storage device Which uses removable media and so is also
tridge because the tape
s/W unload removal
drive is in use. Wait until
attempted
tridge.
45
11 Cleaning
I
Media
has been a reduction in the
tables
W
The tape drive is having
See
problems Writing data. No
sub
data has been lost, but there
sequent
has been a reduction in the
tables
W The operation has stopped
Error
because an error has oc-
curred While reading or
Writing data Which the drive
C
Your data is at risk:
1. Copy any data you re-
quire from this tape.
2. Do not use this tape
restore, insert a data-grade
tape.
during
backup or
(R)
12 Unsup-
I
ported
Format
You have tried to load a
Attempted On load
cartridge of a type Which is
not supported by this drive.
loaded of of valid
unsup- format
The cartridge has been
automatically ejected.
55
3. Restart the operation
ported
tape
tape for- (includ
mat, e.g. ing
DDSZ in cleaning
See
DDS1
sub
drive
sequent
tables
13 Snapped
Tape
C
20 Clean
C
See
sub
sequent
tables
again.
With a different tape.
tape en- eject
restore
cannot correct.
4 Media
media
removal
on (R)
Cleaning On tape
countered
capacity of the tape.
3 Hard
When
prevent
If you Want to back up or
sub
capacity of the tape.
2 Write
The tape in the drive is a
cleaning cartridge.
Cleared
See
sequent
attempted
Manual or On lock
before ejecting the car-
TABLE 1
data has been lost, but there
is
You cannot eject the car-
the operation is complete
relevant to optical disc drives.
problems reading data. No
On tape
command eject
protected
tape (R)
the Internet from a source such as a World Wide Web or FTP
The tape drive is having
Write
to a Write
softWare could be doWn-loaded accross, a netWork such as
W
grade
media data
grade
detect
enabled
25
The backup controller softWare may be con?gured to
automate the recommended maintenance/recovery actions,
particularly if there are multiple tape drives or autochangers
present. For example, it could trigger performance of a
cleaning cycle for ?ags 20 and 21, or a tape copy for ?ags
4 and 7, and retire the suspect media.
Typically, the backup controller softWare Will be loaded
1 Read
life
The tape cartridge is not
prevent the failure occurring at all, and thus increases the
Cause
tables
(NR)
user or the backup controller softWare can initiate actions to
Type Required Host Message
sequent
life:
1. Copy any data you need
2. Discard the old tape.
The backup controller softWare does not fail a backup job
based on the ?ag information. Rather, setting of the ?ags
provides preventative maintenance information such that the
No Flag
tables
See
sub
W The tape cartridge has
The media On tape
reached the end of its useful
has
eject
error messages together in one dialogue box.
into the memory of the host computer from a computer
readable data carrying medium such as a ?oppy disk,
sequent
helpline.
Ware so that only errors of a certain severity are noti?ed to
reliability of the backup system. This facility also provides
assistance in diagnosing/recovering a failing backup job.
Cleared
2. If the problem persists,
call the tape drive supplier
include error message ?lters in the backup controller soft
the user and/or specifying the mode of noti?cation of errors
See
drive is faulty. Call the tape
faulty:
10
are set simultaneously they are listed in ascending order of
Cause
The tape is damaged or the
supplier helpline.
error message along With details to identify Which tape drive
the error refers to, and the softWare label of the media for
media related actions (?ags 4 and 7). The noti?cation
identi?es the severity of the error, and When multiple ?ags
Type Required Host Message
NoW
65
tape)
The operation has failed beTape
On next
cause the tape in the drive snapped in media
has snapped:
the drive load
1. Discard the old tape.
(NR)
2. Restart the operation
With a different tape.
The tape drive needs clean-
See
ing:
1. If the operation has
stopped, eject the tape and
sub
sequent
tables
US 6,263,454 B1
No Flag
21 Clean
Periodic
17
18
TABLE l-continued
TABLE l-continued
Type Required Host Message
clean the drive
2. If the operation has not
stopped, Wait for it to ?nish
and then clean the drive.
The tape drive is due for
routine cleaning:
Cause
Cleared
No Flag
43 Loader
Door
Type Required Host Message
C
because the autoloader
door is open:
1. Clear any obstructions
from the autoloader door.
Not
Supported
1. Wait for the current
The operation has failed
Media
2. Then use a cleaning
3. If the fault does not
cartridge.
clear, turn the autoloader
off and then on again
The last cleaning cartridge
used in the tape drive has
The
Until a
cleaning valid
Worn out:
1. Discard the Worn out
tape has clean is
eXpired carried
cleaning cartridge.
(R)
Cleared
Tape
changer
door open
2. Eject the magazine and
then insert it again.
10
operation to ?nish.
22 Expired
Cleaning
Cause
4. If the problem persists,
call the tape drive supplier
helpline.
out
64
2. Wait for the current
operation to ?nish.
3. Then use a neW cleaning
cartridge.
30 HardWare
A
The tape drive has a hard-
See
Ware fault:
sub
1. Eject the tape or
magazine.
TABLE 2
RAW Retries
sequent
tables
Criteria
2. Reset the drive (hold the
unload button doWn for 5
25
seconds).
1 Read
The Tape Drive is having
2 Write
The Tape Drive is having
B
The tape drive has a hard-
See
Ware fault:
sub
1. Turn the tape drive off
and then on again.
sequent
tables
3 Hard Error
A Hard Error has
occurred
4 Media
You are advised to copy
The tape drive has a prob-
The drive
lem With the SCSI interface:
has
identi?ed
33 Eject
Media
2. Restart the operation.
The operation has failed:
1. Eject the tape or
magazine.
5 Read Fail
an
6 Write Fail
interfacing
faulty batch of media, or
action
media or call the service
the tape drive is faulty.
Please use knoWn good
engineer
20 Clean Now
3. Restart the operation.
tried to use the incorrect
Firmware
doWnload
SET
hardWare fault, try a soft
45
reset
31 HardWare B The tape drive has a
Obtain the correct ?rmWare
hardWare fault, try
poWering the tape drive
and try again.
HardWare
A
The tape drive heads need
cleaning, use a cleaning
cartridge noW.
30 HardWare A The tape drive has a
failed
?rmWare for this tape drive.
40 Loader
You may either have a
fault
Error
recovery
magazine again.
The ?rmWare doWnload has
failed because you have
You may either have a
damaged tape, or the tape
drive is faulty. Please call
the service engineer
35
2. Insert the tape or
34 DoWnload
Fail
SET
another tape and discard
this tape
helpline.
1. Check the cables and
SET
any data that you need to
3. If the problem persists,
call the tape drive supplier
cable connections.
SET
problems Writing data
2. Restart the operation.
32 Interface
State 2
problems reading data
3. Restart the operation.
31 HardWare
State 1
The changer mechanism is
Loader
having di?iculty communicating With the tape drive:
mech. is
having
1. Turn the autoloader off
trouble
then on.
communi
2. Restart the operation.
3. If problem persists, call
the tape drive supplier
cating
With the
tape drive
off and then on again
State Change
State Machine: States 1/2
Criteria
State 1 if >24 hrs from
last clean
State 2 if <24 hrs from
last clean
helpline.
41 Loader
Stray
Tape
A tape has been left in the
autoloader by a previous
hardWare fault:
1. Insert an empty maga-
Zine to clear the fault.
2. If the fault does not
clear, turn the autoloader
off and then on again.
Stray tape
left in
loader
55
TABLE 3
after
pervious
error
1 Read
2 Write
helpline.
B
There is a problem With the
autoloader mechanism.
Read Retries
State 1
State 2
The Tape Drive is having
SET
SET
problems reading data
3. If the problem persists,
call the tape drive supplier
42 Loader
HardWare
Criteria
recovery
The Tape Drive is having
problems Writing data
See
sub
sequent
tables
65
3 Hard Error
A Hard Error has
occurred
4 Media
You are advised to copy
any data that you need to
SET
US 6,263,454 B1
19
20
TABLE 3-c0ntinued
TABLE 3-c0ntinued
Read Retries
Cntena
State 1
State 2
5
another tape and discard
this tape
5 Read Fail
6 Write Fail
30 HardWare A The tape drive has a
You may either have a
hardWare fault, try a soft
damaged tape, or the tape
drive is faulty. Please call
the service engineer
reset
31 HardWare B The tape drive has a
10
hardWare fault, try
poWering the tape drive
You may either have a
faulty batch of media, or
off and then on again
the tape drive is faulty.
Please use knoWn good
State Change
Any tape load
media or call the service
Criteria
Cycle 121212 etc
EXcept state 1 if >24 hrs
from last clean
engineer
20 Clean NoW
Read Retries
State 1
State 2
Criteria
The tape drive heads need
cleaning, use a cleaning
cartridge noW
15
SET
TABLE 4
Read Error
Write Error
Codes: 9X +
Codes: 8X +
Tape Mgmt
Tape l\_/Igmt
Criteria
Occurrence
1 Read
HardWare
Error Codes:
2nd and
1st
2nd
3rd
1st
2nd
3rd
1st
subs
Set
Set
Set
Set
Set
Set
Set
Set
The Tape
Drive is
having
problems
2 Write
reading data
The Tape
Drive is
having
problems
Writing data
3 Hard
Error
A Hard
Error has
occurred
4 Media
You are
Set
Set
advised to
copy any
data that you
need to
another tape
and discard
this tape
5 Read
Failure
Set
You may
either have a
damaged
tape, or the
tape drive is
faulty.
Please call
the service
engineer
6 Write
Failure
Set
You may
either have a
faulty batch
of media, or
the tape
drive is
faulty.
Please use
knoWn good
media or
call the
service
engineer
20 Clean
NoW
The tape
drive heads
need
cleaning,
use a
Set
Set
US 6,263,454 B1
21
22
TABLE 4-c0ntinued
Read Error
Write Error
Hardware
Codes: 9X +
Codes: 8X +
Error Codes:
Tape Mgrnt
Tape l\_/Igrnt
Criteria
Occurrence
1st
2nd
3rd
1st
2nd
2nd and
3rd
1st
subs
cleaning
cartridge
now
30
The tape
HardWare
drive has a
A
Set
hardWare
fault, try a
soft reset
31
The tape
HardWare
drive has a
B
hardWare
Set
fault, try
powering
the tape
drive off
and then on
again
State
Cln
Md
Change
Cycle
Md
Cln
Md
Md
Soft
Hard
Reset
Reset
N/A
123123123etc
pattern
Except state 1 if >24 hours from last
clean
TABLE 5
7
6
5
4
30
3
O
Page Code O><2e
1
2
Reserved (0)
Page Length
3
4
2
1
0
36
35
Parameter Code (1)
DU
(0)
DS(1)
TSD(O) ETC(O) TMC(O) Res(O)
7
8
Parameter Length (1)
Read Flag
9
10
Parameter Code (2)
11
DU
(0)
DS(1)
TSD(O) ETC(O) TMC(O) Res(O)
12
13
Pararneter Length (1)
Write Flag
14
15
Pararneter Code (3)
16
DU
(0)
DS(1)
TSD(O) ETC(O) TMC(O) Res(O)
17
Pararneter Length (1)
18
19
20
Hard Error Flag
Pararneter Code (4)
21
DU
(0)
DS(1)
TSD(O) ETC(O) TMC(O) Res(O)
22
Pararneter Length (1)
23
24
25
Media Flag
Pararneter Code (5)
26
DU
(0)
DS(1)
TSD(O) ETC(O) TMC(O) Res(O)
27
Pararneter Length (1)
28
29
30
Read Failure Flag
Pararneter Code (6)
31
DU
(0)
DS(1)
TSD(O) ETC(O) TMC(O) Res(O)
32
Pararneter Length (1)
33
34
Write Failure Flag
Pararneter Code (7)
7
6
DU
(O)
DS(1)
5
4
3
2
1
0
35
5
6
TABLE 5-c0ntinued
LP(O)
Pararneter Length (1)
Media Life Flag
39
Pararneter Code (8)
40
41
40
LP(O)
DU
DS(1)
TSD(O) ETC(O) TMC(O) Res(O)
LP(O)
LP(O)
(O)
42
Pararneter Length (1)
43
44
Not Data Grade Flag
Pararneter Code (9)
45
46
45
LP(O)
TSD(O) ETC(O) TMC(O) Res(O)
37
38
DU
DS(1)
TSD(O) ETC(O) TMC(O) Res(O)
LP(O)
(O)
47
Pararneter Length (1)
48
49
Write Protect Flag
Pararneter Code (OXA)
50
51
DU
DS(1)
TSD(O) ETC(O) TMC(O) Res(O)
LP(O)
(O)
50
LP(O)
52
53
54
55
56
Pararneter Length (1)
No Rernoval Flag
Pararneter Code (OXB)
DU
DS(1)
TSD(O) ETC(O) TMC(O) Res(O)
LP(O)
(O)
55
LP(O)
57
58
59
60
61
Pararneter Length (1)
Cleaning Media Flag
Pararneter Code (OxC)
DU
DS(1)
TSD(O) ETC(O) TMC(O) Res(O)
LP(O)
(O)
60
LP(O)
62
63
64
65
66
Pararneter Length (1)
Unsupported Format Flag
Pararneter Code (OXD)
DU
DS(1)
TSD(O) ETC(O) TMC(O) Res(O)
(O)
65
67
68
Pararneter Length (1)
Tape Snapped Flag
LP(O)
US 6,263,454 B1
TABLE 5-continued
7
6
5
4
3
TABLE 5-continued
2
1
0
Parameter Code
7
5
6
5
209
4
3
2
1
0
Parameter Code (0><2A)
210
DU
DS(1)
(0)
. . .
99
TSD(0) ETC(0) TMC(0) Res(0)
LP(O)
211
102
TSD(0) ETC(0) TMC(0) Res(0)
212
XXXXXXXXXXXXXXXXX
213
Loader HardWare B Flag
214
Parameter Code (0><2A)
Parameter Code (0x14)
10
DU
DS(1)
(0)
TSD(0) ETC(0) TMC(0) Res(0)
LP(O)
216
Parameter Length (1)
217
Clean NoW Flag
218
104
105
Parameter Code (0x15)
DU
DS(1)
TSD(0) ETC(0) TMC(0)
15
Parameter Length (1)
Res(0)
LP(O)
DU
DS(1)
TSD(0) ETC(0) TMC(0) Res(0)
(0)
. . .
Loader Door Flag
Parameter Code
DU
DS(1)
TSD(0) ETC(0) TMC(0)
Res(0)
LP(O)
TSD(0) ETC(0) TMC(0) Res(0)
LP(O)
(0)
107
Parameter Length (1)
. . .
108
Clean Periodic Flag
. . .
XXXXXXXXXXXXXXX
109
Parameter Code (16)
319
Parameter Code (40)
20
110
112
DU
DS(1)
(0)
TSD(0) ETC(0) TMC(0) Res(0)
LP(O)
DU
(0)
321
Parameter Length (1)
322
Expired Cleaning Media Flag
323
Parameter Code
DS(1)
(0)
Parameter Length (1)
XXXXXXXXXXXXXXX
LP(O)
TABLE 6
Parameter Length (1)
Parameter Code (1E)
DU
(O)
DS(1)
7
TSD(0) ETC(0) TMC(0) Res(0)
LP(O)
30
152
Parameter Length (1)
2
HardWare A Flag
3
154
Parameter Code (1F)
4
155
6
5
4
O
1
153
3
2
1
O
Reserved
LogE IT
Page Code (oxlc)
Page Length (0><0A)
Perf
Reserved
DEXcpt
Test
Reserved
MRIE
Interval Timer
5
157
Parameter Length (1)
6
7
8
158
159
HardWare B Flag
Parameter Code (20)
9
10
DU
(0)
DS(1)
TSD(0) ETC(0) TMC(0) Res(0)
LP(O)
35
160
161
DU
25
DS(1) TSD(0) ETC(0) TMC(0) Res(0)
. . .
156
Parameter Length (1)
320
113
151
LP(O)
Parameter Length (1)
. . .
(0)
111
LP(O)
215
103
106
DS(1)
(0)
Parameter Length (1)
100
101
DU
Report Count
11
DU
DS(1)
TSD(0) ETC(0) TMC(0) Res(0)
LP(O)
4O
(0)
162
Parameter l?ngth (1)
163
Interface Flag
164
Parameter Code (21)
165
166
DU
DS(1)
What is claimed is:
1. A system for storing computer data comprising:
.
TSD(O) ETC(O) TMC(O) Res(0)
LP(0)
(0)
45
167
168
Parameter
Lf’ngth (1)
EJect Media Flag
169
Parameter Code (21)
170
171
DU
(0)
DS(1)
.
Wherein the storage device comprises:
.
.
.
.
means to perform error diagnosis of interactions
TSD(0) ETC(0) TMC(0) Res(0)
LP(0)
50
psgigrl?gegdlggigtgli)
_ _ _
.
a storage device havmg means for readmg data from and
Writing data to removable media;
and a controller,
between the storage device and the controller and to
translate loW-level error indicators into a plurality of
high level error conditions;
means to communicate occurrence of these high level
Parameter Code (XX)
error conditions to the controller to trigger the pro
vision of error messages to the user;
DU
(0)
DS(1)
TSD(0) ETC(0) TMC(0) Res(0)
h
LP(0)
55
Parameter Lang (1)
199
200
201
loW-level error has occurred.
Parameter Code (0X28)
12)‘;
means for communicating different high level error
conditions according to hoW many times a speci?ed
2. A system accordmg to claim 1, further comprising
means for communicating different combinations of high
135(1) T5D(0) ETC(O) TMC(0) Resw)
LP(O)
level error conditions according to hoW many times a
202
203
Parameter Length (1)
Loader Hardware A Flag
60 particular loW-level error has occurred.
.
3. A system accordmg to claim 1, wherein the loW-level
204
205
Parameter Code (0x29)
error indicators are grouped into functional types and
Wherein a predetermined sequence of high level error con
206
DU
(O)
DS(1)
TSD(0)
ETC(0) TMC(0)
207
Parameter L?ngth (1)
208
Stray Tape Flag
Res(0)
LP(O)
d-itions
- communicate
d accor d-mg to h oW many times
1s
a
65 loW-level error of the same functional type has occurred.
4. A system comprising means for communicating differ
ent high for storing computer data comprising:
US 6,263,454 B1
25
26
a storage device having means for reading data from and
means for communicating different high level error con
ditions according to hoW many times a speci?ed loW
Writing data to removable media; and
level error has occurred.
a controller,
14. A host computer comprising controller means
Wherein the storage device comprises:
5 arranged for operation in a system that includes a storage
means to perform error diagnosis of interactions
device having means for reading data from and Writing data
betWeen the storage device and the controller and to
to removable media, said host computer further comprising:
translate loW-level error indicators into a plurality of
means to perform error diagnosis of interactions betWeen
the storage device and the controller and to translate
loW-level error indicators into a plurality of high level
error conditions;
means to communicate occurrence of these high level
error conditions to the controller to trigger the provi
high level error conditions;
means to communicate occurrence of these high level
error conditions to the controller to trigger the pro
vision of error messages to a user; and
means for communicating different high level error
conditions according to hoW many times a speci?ed
loW-level error has occurred and according to the
elapsed time since the storage device Was last
cleaned.
5. A system according to claim 1, Wherein the error
messages are categoriZed according to severity.
6. Asystem according to claim 5, Wherein error messages
are grouped into three categories of severity.
7. A system according to claim 1, further comprising
means for automatically initiating a predetermined sequence
sion of error messages to the user;
means for communicating different high level error con
ditions according to hoW many times a speci?ed loW
level error has occurred.
15. A computer usable medium having computer readable
20
program code means embodied in said medium executable
by a host computer to perform as a controller function during
the storing of computer data, said host computer including
a storage device having means for reading data from and
of error recovery steps according to the high level error
conditions identi?ed.
8. A system according to claim 1, Wherein error informa
tion is developed by said controller from said error indica
Writing data to removable media, Wherein the computer
usable medium comprises:
tors and error status information indicative of said error
and said controller function and to translate loW-level
error indicators into a plurality of high level error
means for controlling the host computer to perform error
diagnosis of interactions betWeen the storage device
information is stored in the storage device in a standardiZed
format.
conditions;
means for controlling the host computer to communicate
9. A system according to claim 1, Which is con?gured so
occurrence of these high level error conditions to the
that an occurrence of high level error conditions is commu
controller function to trigger the provision of error
messages to the user; and
means for controlling the host computer to communicate
different high level error conditions according to hoW
nicated to the controller at predetermined points in a storage
operation.
10. A system according to claim 1 Which is con?gured so
that the occurrence of high level error conditions is com
municated to the controller Whenever a neW error is indi
many times a speci?ed loW-level error has occurred.
cated by the storage device.
11. A system according to claim 1, Wherein the system
comprises a plurality of storage devices.
12. A system according to claim 1, Wherein the storage
16. A method for storing computer data comprising the
steps of:
reading data from and/or Writing data to removable
media;
device is a tape drive.
performing error diagnosis on the basis of any loW-level
13. A storage device arranged for operation in a system
and having means for reading data from and Writing data to
removable media and a controller, the storage device com
prising:
means to perform error diagnosis of interactions betWeen
the storage device and the controller and to translate
loW-level error indicators into a plurality of high level
error conditions;
means to communicate occurrence of these high level
error conditions to the controller to trigger the provi
sion of error messages to the user; and
error indicators resulting from said reading and/or
Writing step;
45
translating said loW-level error indicators into a plurality
of high level error conditions, Wherein different high
level error conditions result according to hoW many
times a speci?ed loW-level error has occurred; and
triggering the provision of error messages to a user of the
system on the basis of the occurrence of these high
level error conditions.
UNITED STATES PATENT AND TRADEMARK OFFICE
CERTIFICATE OF CORRECTION
PATENT NO.
DATED
: 6,263,454 B1
1 July 17, 2001
INVENTOR(S)
: Gold et a1.
Page 1 of l
It is certified that error appears in the above-identified patent and that said Letters Patent is
hereby corrected as shown below:
Column 24, claim 4,
Lines 66 & 67, change "A system comprising means for communicating different high
for storing computer data comprisingz" to -- A system for storing computer data
comprising: -
Signed and Sealed this
Nineteenth Day of March, 2002
JAMES E. ROGAN
Arresting Officer
Director ofrhc U11 fled States Parent and Trademark O?ir'c‘
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