Hardware for Shared Storage. EMC FC4500, FC5300, FC5700

4

Planning LUNs and File Systems with Unshared Direct Storage

Dual SPs and Paths to LUNs

If a storage system has two SPs, there are two routes to its LUNs. If the server has two adapters and the storage system has two SPs,

Application Transparent Failover (ATF). ATF can automatically switch to the other path, without disrupting applications, if a device

(such as a host-bus adapter, cable, or SP) fails.

Unshared Direct and Shared-or-Clustered Direct Storage

This section explains the direct (unswitched) options available for connecting storage systems to servers. As needs change, you may want to change a configuration. You can do so without changing your

LUN configuration or losing user data.

There are two types of installation:

• Unshared direct with one server is the simplest and least costly;

• Shared-or-clustered direct lets two clustered servers share storage resources with high availability.

Sample Unshared Direct Installation

Server

Disk IDs

100-109

010-019

SP A

Database

RAID 5

Sys

RAID 1

SP B

Users

RAID 5

Clients, mail

RAID 5

Figure 4-1 Unshared Direct Installation

Path 1

Path 2

EMC1825

4-2

EMC Fibre Channel Storage Systems Configuration Planning Guide


4

The storage system disk IDs and LUNs are as follows. The LUN capacities shown assume 36-Gbyte disks.

LUNs - SP A and SP B, 422 Gbytes

Disk IDs RAID type, storage type, capacity

0_0, 0_1 RAID 1, System disk, 36 Gbytes

0_2-0_9 RAID 5 (8 disks), Clients and Mail, 216 Gbytes

1_0-1_4 RAID 5, Database, 144 Gbytes

1_5 Disk, Temporary storage, 36 Gbytes

Sample Shared-or-Clustered Direct Installation

Server 1 (S1) Server 2 (S2)

Storage system

SP A

S2 Customers

RAID 5

SP B

S1Dbase

RAID 5

Path 1

Path 2

Figure 4-2 Sample Clustered Installation

If each disk holds 36 Gbytes, then the storage-system chassis provides

Server 1 with 256 Gbytes of disk storage, 220 Gbytes highly available; it provides Server 2 with 216 Gbytes of storage, all highly available.

Each server has its own SP, which controls that server’s LUNs; those

LUNs remain primary to that server. The LUNs are as follows.

Server1 LUNs (S1) - SP A, 256 Gbytes


0_0, 0_1 RAID 1, System disk, 36 Gbytes

0_2 Disk, Temporary storage, 36 Gbytes

0_3-0_7 RAID 5, Database, 144 Gbytes

0_8-0_ 9 RAID 1, Users, 36 Gbytes

Server2 LUNs (S2) - SP B, 216 Gbytes


1_0-1_7 RAID 5 (8 disks), Cust Accounts, 216

Gbytes

Unshared Direct and Shared-or-Clustered Direct Storage 4-3

4


Planning Applications and LUNs

This section helps you plan your unshared (direct) storage use — applications you want to run and the LUNs that will hold them. The worksheets to help you do this include

• Application and file system planning worksheet - lets you outline your storage needs.

• LUN planning worksheet - lets you decide on the disks that will compose the LUNs.

• LUN details worksheet - lets you plan each LUN in detail.

Make as many copies of each blank worksheet as you need. You will need this information later when you configure the shared storage system.

Sample file system, Storage Group, and LUN worksheets appear later in this chapter.

Application and LUN Planning

Use the following worksheet to plan your file systems and RAID types. For each application, write the application name, file system (if any), RAID type, LUN ID (ascending integers, starting with 0), disk space required, and finally the name of the servers and operating systems that will use the LUN.

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4

Application and LUN Planning Worksheet

Application File system (if any)

RAID type of

LUN

LUN

ID (hex)

Disk space required

(Gbytes)

Server name and operating system

Application

Mail 1

Mail 2

Database index

A sample worksheet begins as follows:

File system (if any)

RAID type of

LUN

RAI D 5

RAI D 5

RAI D 1 2

0

1

LUN

ID (hex)

Disk space required

(Gbytes)

72 Gb

72 Gb

18 Gb

Server name and operating system

Server1, NT

Server1, NT

Server2, NT

Completing the Application and LUN Planning Worksheet

Application . Enter the application name or type.

File system, partition , or drive. Write the drive letter (for Windows only) and the partition, file system, logical volume, or drive letter

(Windows only) name.

With a system such as Windows NT, the LUNs are identified by drive letter only. The letter does not help you identify the disk configuration (such as RAID 5). We suggest that later, when you use the operating system to create a partition on the unit, you use the disk administrator software to assign a volume label that describes the

Planning Applications and LUNs 4-5

4


RAID configuration. For example, for drive T, assign the volume ID

RAID5_T . The volume label will then identify the drive letter.

RAID type of LUN is the RAID Group type you want for this partition, file system, or logical volume. The features of RAID types

are explained in Chapter 2. For a RAID 5, RAID 1, RAID 1/0, and

RAID 0 Group, you can create one or more LUNs on the RAID

Group. For other RAID types, you can create only one LUN per RAID

Group.

LUN ID is a hexadecimal number assigned when you bind the disks into a LUN. By default, the ID of the first LUN bound is 0, the second

1, and so on. Each LUN ID must be unique within the storage system, regardless of its Storage Group or RAID Group.

The maximum number of LUNs supported on one host-bus adapter depends on the operating system. Some systems allow only eight

LUNs (numbers 0 through 7). For an operating system with this restriction, if you want a hot spare, assign the hot spare an ID above

7; for example, 8 or 9. The operating system never accesses a hot spare, so the ID is irrelevant to it.

Disk space required (Gbytes) , Consider the largest amount of disk space this application will need, then add a factor for growth.

Server hostname and operating system Enter the server hostname

(or, if you don’t know the name, a short description that identifies the server) and the operating system name, if you know it.

If this storage system will be used by two servers, provide a copy of this worksheet to the other server. This is particularly important where one server may take over the other’s LUNs. If a LUN will be shared, on the Notes section of the LUN details worksheet, write

Primary to server-name or Secondary to server-name.

LUN Planning Worksheet

Use one of the following worksheets (Rackmount or Deskside) to select the disks that will make up the LUNs. Depending on model, a full-fibre rackmount storage system can include up to 100 disks, numbered 0 through 99, left to right from the bottom up.

Again depending on model, a deskside storage system can hold ten,

20, or 30 disks.

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4

LUN Planning Worksheet - Rackmount

Full-fibre storage system

11_0 11_1 11_2 11_3 11_4 11_5 11_6 11_7 11_8 11_9

10_0 10_1 10_2 10_3 10_4 10_5 10_6 10_7 10_8 10_9

9_0 9_1 9_2 9_3 9_4 9_5 9_6 9_7 9_8 9_9

8_0 8_1 8_2 8_3 8_4 8_5 8_6 8_7 8_8 8_9

7_0 7_1 7_2 7_3 7_4 7_5 7_6 7_7 7_8 7_9

6_0 6_1 6_2 6_3 6_4 6_5 6_6 6_7 6_8 6_9

5_0 5_1 5_2 5_3 5_4 5_5 5_6 5_7 5_8 5_9

4_0 4_1 4_2 4_3 4_4 4_5 4_6 4_7 4_8 4_9

3_0 3_1 3_2 3_3 3_4 3_5 3_6 3_7 3_8 3_9

2_0 2_1 2_2 2_3 2_4 2_5 2_6 2_7 2_8 2_9

1_0 1_1 1_2 1_3 1_4 1_5 1_6 1_7 1_8 1_9

0_0 0_1 0_2 0_3 0_4 0_5 0_6 0_7 0_8 0_9

LUN number_______RAID type ___ Cap. (Gb) _____ Disk IDs_________________________________________









4


LUN Planning Worksheet - Deskside

Full-fibre storage system

0_0

0_1

0_2

0_3

0_4

0_5

0_6

0_7

0_8

0_9

1_0

1_1

1_2

1_3

1_4

1_5

1_6

1_7

1_8

1_9

2_4

2_5

2_6

2_7

2_8

2_9

2_0

2_1

2_2

2_3

Storage system number_____

LUN number_______RAID type ___ Cap. (Gb) _____ Disk IDs________________________________________








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4

A sample LUN worksheet follows.

2_0 2_1 2_2 2_3 2_4 2_5 2_6 2_7 2_8 2_9

LUN 2

RAID 1

1_0 1_1 1_2 1_3 1_4 1_5 1_6 1_7 1_8 1_9

LUN 0

RAID 5

0_0 0_1 0_2 0_3 0_4 0_5 0_6 0_7 0_8 0_9

LUN 1

RAID 5

0

5

144

0_0, 0_1, 0_2, 0_3, 0_4


2

5

36 1_0, 1_1





Completing the LUN Planning Worksheet

As shown, draw circles around the disks that will compose each

LUN, and within each circle specify the RAID type (for example,

RAID 5) and LUN ID. This is information you will use to bind the disks into LUNs. For disk IDs, use the form shown. This form is

enclosure_diskID, where enclosure is the enclosure number (the bottom one is 0, above it 1, and so on) and diskID is the disk position (left is 0, next is 1, and so on).

None of the disks 0_0 through 0_8 may be used as a hot spare.

LUN Details Worksheet

Next, complete as many of the LUN sections as needed for each storage system.Copy the (blank) worksheet as needed for all LUNs in each storage system. A storage system is any group of enclosures connected to a DPE; a full-fibre system can include up to nine DAE enclosures for a total of 100 disks.

Use the following LUN details worksheet to plan the individual

LUNs. Complete as many of these as needed for all LUNs.


4



Storage system (complete this section once for each storage system)

Storage-system number or name:______

Storage-system installation type

❏ Unshared Direct ❏ Shared-or-Clustered Direct ❏ Shared Switched

SP FC-AL address ID (unshared only):

SP memory (Mbytes):

V Use for caching

V Use for RAID 3

SP A:______

SP A:_____SP B:_____

SP B:______

Read cache size:___ MB Write cache size: ___ MB Cache page size:___KB

LUN ID:_____

RAID Group ID: Size,GB:

RAID type: V RAID 5

V RAID 1/0

V

V

LUN size,GB: Disk IDs:

RAID 3 - Memory, MB:___

Individual disk

Caching: V Read and write V Write V Read V None

SP: V A V B

V RAID 1 mirrored pair V RAID 0

V Hot spare

Servers that can access this LUN:

Operating system information: Device name: File system, partition, or drive:

LUN ID:_____

RAID Group ID: Size,GB: LUN size,GB: Disk IDs:

RAID type: V RAID 5

V RAID 1/0

V

V


Individual disk



Operating system information: Device name:

V A V B


V Hot spare

SP:

File system, partition, or drive:

RAID Group ID: Size,GB:

LUN ID:_____

LUN size,GB: Disk IDs:

RAID type: V RAID 5

V RAID 1/0

V

V


Individual disk




V A V B


V Hot spare

SP:


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4


Storage system (complete this section once for each storage system)

Storage-system number or name:__ 1 ____

Storage-system installation type

❏ Unshared Direct ❏ Shared-or-Clustered Direct ❏ Shared Switched

SP FC-AL address ID (unshared only): SP A:_____SP B:_____

SP memory (Mbytes):

V X Use for caching

V Use for RAID 3

SP A:_ 128 __ SP B:_ 128 __

Read cache size:_ 40 _ MB Write cache size: _ 80 _ MBCache page size:_ 2 __KB

LUN ID:__ 0 ___

RAID Group ID: 0 Size,GB: 144 LUN size,GB: 144

0_0, 0_1, 0_2, 0_3, 0_4

RAID type: V RAID 5

V

RAID 1/0

V RAID 3 - Memory, MB:___

V

Individual disk

Caching:

X

Read and write V Write V Read V None

SP: X A V B


V

Hot spare

Servers that can access this LUN: Server1

Operating system information: Device name: File system, partition, or drive:

T

LUN ID:__ 1 __

RAID Group ID: 1 Size,GB: 144 LUN size,GB: 144 Disk IDs:

0_5, 0_6, 0_7, 0_8, 0_9

SP: V A V B

RAID type:

X

RAID 5

V RAID 1/0


V Individual disk

Caching:

V

Read and write

V

Write

V

Read

V

None


V Hot spare

Servers that can access this LUN: Server1

Operating system information: Device name: File system, partition, or drive: U

RAID Group ID: 2 Size,GB:

18

LUN ID:__ 2 __

LUN size,GB: 36 Disk IDs:

RAID type: V RAID 5

V RAID 1/0


V Individual disk


Servers that can access this LUN: Server1


1_0, 1_1


SP: X A V B

X V RAID 1 mirrored pair V RAID 0

V Hot spare

V


4


Completing the LUN Details Worksheet

Complete the header portion of the worksheet for each storage system as described below. Copy the blank worksheet as needed.

Sample completed LUN worksheets appear later.

Storage-System Entries

Storage-system configuration . Specify Unshared Direct (one server) or Shared-or-Clustered Direct (two servers).

For any multiple-server configuration, each server will need cluster software.

SP FC-AL address ID . For unshared storage, which uses FC-AL addressing, each SP (and each other node) on a Fibre Channel loop must have a unique FC-AL address ID. You set the SP FC-AL address

ID using switches on the back panel of the SP. The valid FC-AL address ID range is a number 0 through 125 decimal, which is 0 through 7D hexadecimal. For any number above 9, we suggest hexadecimal, since the switches are marked in hexadecimal.

If you have two FC-AL loops, we suggest a unique FC-AL address ID for each SP on both loops.

SP memory . Enter the amount of memory each SP has. If a storage system has two SPs, they will generally have the same amount of memory. You can allocate this memory to storage-system caching or

RAID 3 use.

Use memory for caching . You can use SP memory for read/write caching or RAID 3. (Using both caching and RAID 3 in the same storage system not recommended.) You can use different cache settings for different times of day (for example, for user I/O during the day, use more write cache; for sequential batch jobs at night, use more read cache. You enable caching for specific LUNs — allowing you to tailor your cache resources according to priority. If you choose caching, check the box and continue to the next step; for RAID 3, skip to the RAID Group ID entry.

Read cache size . If you want a read cache, it should generally be about one third of the total available cache memory.

Write cache size . The write cache should be two thirds of the total available. Some memory is required for system overhead, so you cannot determine a precise figure at this time. For example, for 256

Mbytes of total memory, you might have 240 Mbytes available, and

4-12



4 you would specify 80 Mbytes for the read cache and 160 Mbytes for the write cache.

Cache page size . This applies to both read and write caches. It can be

2, 4, 8, or 16 Kbytes. As a general guideline, we suggest

For a general-purpose file server — 8 Kbytes

For a database application — 2 or 4 Kbytes

The ideal cache page size depends on the operating system and application.

Use memory for RAID 3 . If you want to use the SP memory for

RAID 3, check the box.

RAID Group/LUN Entries

Complete a RAID Group/LUN entry for each LUN and hot spare.

LUN ID . The LUN ID is a hexadecimal number assigned when you bind the disks into a LUN. By default, the ID of the first LUN bound is 0, the second 1, and so on. Each LUN ID must be unique within the storage system, regardless of its Storage Group or RAID Group.

The maximum number of LUNs supported on one host-bus adapter depends on the operating system. Some systems allow only eight

LUNs (numbers 0 through 7). For an operating system with this restriction, if you want a hot spare, assign the hot spare an ID above

7; for example, 8 or 9. The operating system never accesses a hot spare, so the ID is irrelevant to it.

RAID Group ID . This is a hexadecimal number assigned when you create the RAID Group. By default, the number of the first RAID

Group in a storage system is 0, the second 1, and so on, up to the maximum of 1F (31).

Size (RAID Group size) Enter the user-available capacity in gigabytes

(Gbytes) of the whole RAID Group. You can determine the capacity as follows:

RAID-5 or RAID-3 Group: disk-size * (number-of-disks - 1)

RAID 1/0 or RAID-1

Group:

(disk-size * number-of-disks) / 2

RAID-0 Group:

Individual unit: disk-size * number-of-disks disk-size


4


For example,

• A five-disk RAID 5 or RAID 3 Group of 36-Gbyte disks holds

144 Gbytes;

• An eight-disk RAID 1/0 Group of 36-Gbyte disks also holds

144Gbytes;

• A RAID 1 mirrored pair of 36-Gbyte disks holds 36 Gbytes; and

• An individual disk of a 36-Gbyte disk also holds 36 Gbytes.

Each disk in the RAID Group must have the same capacity; otherwise, you will waste disk storage space.

LUN Size . Enter the user-available capacity in gigabytes (Gbytes) of the LUN. You can make this the same size as the RAID Group, above.

Or, for a RAID 5, RAID 1, RAID 1/0, or RAID 0 Group, you can make the LUN smaller than the RAID Group. You might do this if you wanted a RAID 5 Group with a large capacity and wanted to place many smaller capacity LUNs on it; for example, to specify a LUN for each user. However, having multiple LUNs per RAID Group may adversely impact performance. If you want multiple LUNs per RAID

Group, then use a RAID Group/LUN series of entries for each LUN.

Disk IDs . Enter the ID(s) of all disks that will make up the LUN or hot spare. These are the same disk IDs you specified on the previous worksheet. For example, for a RAID-5 Group in the DPE (enclosure 0, disks 2 through 6), enter 0_2, 0_3, 0_4, 0_5, and 0_6.

SP . Specify the SP that will own the LUN: SP A or SP B. You can let the management program automatically select the SP to balance the workload between SPs; to do so, leave this entry blank.

RAID type . Copy the RAID type from the previous worksheet. For example, RAID 5 or hot spare. For a hot spare (not strictly speaking a

LUN at all), skip the rest of this LUN entry and continue to the next

LUN entry (if any).

If this is a RAID 3 Group, specify the amount of SP memory for that group. To work efficiently, each RAID 3 Group needs at least

6 Mbytes of memory.

Caching.

If you want to use caching (entry on page 4-12), you can

specify whether you want caching — read and write, read, or write for this LUN. Generally, write caching improves performance far more than read caching. The ability to specify caching on a LUN basis provides additional flexibility, since you can use caching for only the

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4

Table 4-1 units that will benefit from it. Read and write caching recommendations follow.

Cache Recommendations for Different RAID Types

RAID 5 RAID 3

Highly Recommended Not allowed

What Next?

RAID 1 RAID 1/0 RAID 0 Individual Unit

Recommended Recommended Recommended Recommended

Servers that can access this LUN . Enter the name of each server that will be able to use the LUN. Normally, you need to restrict access by establishing SP ownership of LUNs when you bind them.

Operating system information: Device name. Enter the operating system device name, if this is important and if you know it.

Depending on your operating system, you may not be able to complete this field now.

File system, partition, or drive . Write the name of the file system, partition, or drive letter you will create on this LUN. This is the same name you wrote on the application worksheet.

On the following line, write any pertinent notes; for example, the file system mount- or graft-point directory pathname (from the root directory). If this storage system’s chassis will be shared with another server, and the other server is the primary owner of this disk, write secondary . (If the storage system will be used by two servers, we suggest you complete one of these worksheets for each server.)

This chapter outlined the planning tasks for unshared storage systems. If you have completed the worksheets to your satisfaction, you are ready to learn about the hardware needed for these systems

as explained in Chapter 5.


4


4-16


Hardware for Shared Storage. EMC FC4500, FC5300, FC5700

Dual SPs and Paths to LUNs

Unshared Direct and Shared-or-Clustered Direct Storage

Sample Unshared Direct Installation

Sample Shared-or-Clustered Direct Installation

Planning Applications and LUNs

Application and LUN Planning

Application and LUN Planning Worksheet

LUN Planning Worksheet

LUN 0

RAID 5

LUN 1

Completing the LUN Details Worksheet

Related manuals

Table of contents

Hardware for Shared Storage. EMC FC4500, FC5300, FC5700

Dual SPs and Paths to LUNs

Unshared Direct and Shared-or-Clustered Direct Storage

Sample Unshared Direct Installation

Sample Shared-or-Clustered Direct Installation

Planning Applications and LUNs

Application and LUN Planning

Application and LUN Planning Worksheet

LUN Planning Worksheet

LUN 0

RAID 5

LUN 1

Completing the LUN Details Worksheet

Related manuals

EMC

TV DVD Combo FC4500

Bull

a DAS Installation (Fibre Channel Environments)

Bull

DC SPS (Direct Current Standby Power Supply)

Bull

DAS 5300 Deskside Models

Bull

DAS 5300 Rackmount Models

EMC

FC4400

Bull

Escala - TOWER PL and S, E, T

Bull

Planning a DAS

EMC

FC4700

EMC

Outboard Motor FC 55XX/57XX

Dell

EMC Unity XT 380F

Dell EMC

ECS D4500

Table of contents