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HP StorageWorks

Cache LUN XP user guidefor the XP12000/XP10000/SVS200

Part number: T1716-96005Fourth edition: June 2006


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Legal and notice information

Copyright 2005, 2006 Hewlett-Packard Development Company, L.P.

Confidential computer software. Valid license from HP required for possession, use or copying. Consistent with FAR 12.211 and 12.212,Commercial Computer Software, Computer Software Documentation, and Technical Data for Commercial Items are licensed to the U.S. Governmentunder vendors standard commercial license.

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All other brand or product names are or may be trademarks or service marks of and are used to identify products or services of their respectiveowners.

Cache LUN XP user guide for the XP12000/XP10000/SVS200


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Cache LUN XP user guide for the XP12000/XP10000/SVS200 3

About this guide. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5Supported storage platforms and firmware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5Intended audience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5Prerequisites. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5Related documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5Document conventions and symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6HP technical support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6Subscription service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6HP web sites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7Documentation feedback . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

1 Cache LUN Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9Supported volumes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9Cache LUN XP tasks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9Supported emulation types and other parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Supported emulation types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Modified volume types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9Unit of cache area allocation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Number of cache areas allowed. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Restrictions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Cache LUN XP support requirements for CU groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Cache LUN XP modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Priority mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12Priority mode details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12General cache capacity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Bind mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12Bind mode details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12Bind mode and RAID groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Pre-staging. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13Required cache size for Cache LUN XP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Open systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13Mainframe systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Starting Cache LUN XP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16Cache LUN pane. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

CLPR drop-down list. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16Prestaging check box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16LDEV tree . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17LDEV table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17Cache LUN XP pie chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17Cache settings section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17Buttons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Setting (creating) a cache extent. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18Releasing (removing) a cache extent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20Changing an extents mode and pre-staging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Figures1 Cache LUN XP operations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 Example of LBA value setting with LUSE volumes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 Cache LUN pane. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 Multi Set pane. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195 Multi Release window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Contents


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4

Tables1 Document conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 Restrictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 Cache LUN XP icons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17


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About this guide

This guide provides information about:

Perparing for Cache LUN XP operations

Performing Cache LUN XP operations

Supported storage platforms and firmwareIn this guide, the term arrayrefers to the following storage platforms:

HP StorageWorks XP12000 Disk Array

HP StorageWorks XP10000 Disk Array

HP StorageWorks 200 Storage Virtualization System

For information about required firmware versions, see the HP StorageWorks XP Remote Web Console userguide for XP12000/XP10000/SVS200.

Intended audienceThis guide is intended for customers and HP-authorized service providers with knowledge of the following:

Disk array hardware and software

Data processing and RAID storage subsystems and their basic functions

NOTE: The functions described in this manual may be limited, depending on your assigned level of useraccess. Some users will have read-only access while others will have limited or full array access. Foradditional information on users and user groups, please see the HP StorageWorks XP Remote WebConsole user guide.

PrerequisitesPrerequisites for using this product include: Installation of the HP StorageWorks disk array(s)

Installation of the license key for this product

Related documentationThe following documents provide related information:

HP StorageWorks XP glossary

HP StorageWorks XP Remote Web Console user guide for XP12000/XP10000/SVS200

HP StorageWorks Flex Copy XP user guide

HP StorageWorks Auto LUN XP user guide for the XP12000/XP10000/SVS200 HP StorageWorks Business Copy XP user guide for the XP12000/XP10000SVS200

HP StorageWorks Cache LUN XP user guide for XP12000/XP10000/SVS200

HP StorageWorks Continuous Access XP Journal user guide

HP StorageWorks Continuous Access XP user guide for the XP12000/XP10000/SVS200

HP StorageWorks LUN Configuration and Security Manager XP user guide for theXP12000/XP10000/SVS200

You can find these documents at http://www.hp.com/support/rwc/manuals
http://www.hp.com/support/rwc/manuals/http://www.hp.com/support/rwc/manuals/


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6

Document conventions and symbols

CAUTION: Indicates that failure to follow directions could result in damage to equipment or data.

IMPORTANT: Provides clarifying information or specific instructions.

NOTE: Provides additional information.

TIP: Provides helpful hints and shortcuts.

HP technical supportTelephone numbers for worldwide technical support are listed on the HP support web site:http://www.hp.com/support/.

Collect the following information before calling:

Technical support registration number (if applicable)

Product serial numbers Product model names and numbers

Applicable error messages

Operating system type and revision level

Detailed, specific questions

For continuous quality improvement, calls may be recorded or monitored.

Subscription serviceHP recommends that you register your product at the Subscribers Choice for Business web site:http://www.hp.com/go/e-updates.

Table 1 Document conventions

Convention Element

Blue text: Table 1 Cross-reference links and e-mail addresses

Blue, underlined text: (http://www.hp.com) Web site addresses

Bold text Keys that are pressed

Text typed into a GUI element, such as a box

GUI elements that are clicked or selected, such asmenu and list items, buttons, and check boxes

Italic text Text emphasis

Monospace text File and directory names

System output

Code

Commands, their arguments, and argument values

Monospace, italic text Code variables

Command variables

Monospace, bold text Emphasized monospace text
http://www.hp.com/support/http://www.hp.com/go/e-updates/http://www.hp.com/go/e-updates/http://www.hp.com/support/


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After registering, you will receive e-mail notification of product enhancements, new driver versions,firmware updates, and other product resources.

HP web sitesFor additional information, see the following HP web sites:

http://www.hp.com

http://www.hp.com/go/storage

http://www.hp.com/service_locator

http://www.hp.com/support/manuals

http://www.hp.com/support/downloads

http://www.hp.com/support/rwc/manuals

Documentation feedbackHP welcomes your feedback.

To make comments and suggestions about product documentation, please send a message [email protected]. All submissions become the property of HP.
http://www.hp.com/http://www.hp.com/go/storage/http://www.hp.com/support/rwc/manuals/http://www.hp.com/support/rwc/manuals/http://www.hp.com/go/storage/http://www.hp.com/


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8


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1 Cache LUN IntroductionUse HP StorageWorks Cache LUN XP to reserve areas of cache memory on the disk array for storinghigh-use data from the LDEVs. Data access speed is improved because the cache-resident data is availableto the hosts at much faster transfer speeds. This can be applied to both read and write I/O operations.

Supported volumes

Cache LUN XP works with normal volumes, LUSE volumes, and custom volumes (configured through CVS).

Use custom volumes and Cache LUN XP together to achieve higher data access performance (than whenthese features are used separately).

Cache LUN XP tasksUse Cache LUN XP to perform the following tasks:

Setting (creating) a cache extent on page 18

Releasing (removing) a cache extent on page 20

Changing an extents mode and pre-staging on page 21

Figure 1 Cache LUN XP operations

Cache LUN XP requires a portion of cache memory, called the Cache LUN XP cache area. You can

change the capacity of the Cache LUN XP cache area when installing or removing cache memory.Typically, data assigned to Cache LUN XP becomes resident (staged) in cache after it is first accessed by ahost. Then, the host finds the data in cache for the second and subsequent accesses.

Another function, called pre-staging, puts data in the Cache LUN XP cache area when the data is first setup for caching. Pre-staging allows the host to find data in the cache at the first access.

Cache areas (also called cache extents) can be added or removed at any time. Each cache extent isdefined as a range of logical blocks within an LDEV or as an entire LDEV. Logical blocks are defined bystarting and ending Logical Block Addresses (LBAs).

Supported emulation types and other parameters

Supported emulation typesSupported open system emulation types are OPEN-3, OPEN-8, OPEN-9, OPEN-E, OPEN-L, and OPEN-V.Supported mainframe emulation types are 3390-3, 3390-3A, 3390-3B, 3390-3C, 3390-3R, 3390-9,3390-9A, 3390-9B, 3390-9C, 3390-L, 3390-LA, 3390-LB, 3390-LC, 3390-M, 3390-MA, 3390-MB, and3390-MC.

Modified volume typesLUSE (LU Size Expansion) and CVS (custom volume size) volumes can be placed in the Cache LUN XPcache area.

If you want to apply Cache LUN XP to a LUSE volume, you must apply Cache LUN XP to all the LDEVs thatform the LUSE volume.


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10 Cache LUN Introduction

Unit of cache area allocationA Cache LUN XP extent is a range of logical blocks within an LDEV. A logical block is 512 bytes.

For OPEN-V, a cache extent must have at least 128 Logical Block Addresses (LBAs), or 66 KB. For all othersupported open system emulation types, a cache extent must have at least 96 LBAs, or 49.5 KB. This isknown as a cache slot. A cache extent can have a maximum size of an entire LDEV, up to the limits ofCache LUN XP cache memory. Allocate data to Cache LUN XP with a minimum size of 128 LBAs forOPEN-V and 96 LBAs for other than OPEN-V.

For mainframe systems, a cache extent must be at least one cache slot or track (48 KB or 64 KB). Itsmaximum size may be an entire LDEV, up to the limits of Cache LUN XP cache memory. Allocate data toCache LUN XP in units of cylinders and tracks.

Number of cache areas allowed

In DKC: 1,024

In LDEV: 1,024

Restrictions

Table 2 Restrictions

Configuration Restrictions Do not exceed the capacity of the Cache LUN XP cache.

Do not configure an Auto LUN reserved volume for Cache LUN XP.

Do not place an LDEV in cache twice.

You cannot allocate Cache LUN XP cache space for an on-demand LDEV.

If you allocate Cache LUN XP on the Volume Management Area (VMA) volumefor LUN Security XP Extension, set 10,240 LBAs (5 MB or larger) for the startinglogical block address of the user data. To do this, add 10,240 LBAs to the LBAvalue recognized on the host side.

To apply Cache LUN XP to a LUSE volume using Select All Area, you mustapply it to all the LDEVs that form the LUSE volume.

If you want to set Cache LUN XP for an LDEV within a LUSE volume using LBAs,

you must know the exact number of LBAs in each LDEV in the LUSE volume.The number of LBAs listed in the Cache LUN XP panel is only for a single LDEVand does not match the number of LBAs recognized by the host if the mountedvolume is a LUSE volume.

To identify the exact number of LBAs in an LDEV, display the Basic InformationDisplay pane, and determine the parity group to which the LDEV belongs.Next, display the Customized Volume panel and find the exact number of LBAsin the LDEV.

NOTE: For more information about the Basic Information Display pane,refer to the HP StorageWorks XP Remote Web Console user guide. Formore information about customized volumes, refer to the HP StorageWorks

LUN Configuration and Security Manager XP user guide.


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Cache LUN XP support requirements for CU groupsThe local disk array supports a maximum of 65,280 LDEVs for mainframe hosts and a maximum of16,384 LDEVs for open-system hosts. LDEVs for mainframe hosts are divided into four CU groups of16,384 LDEVs each. Each CU group is numbered from 0 to 3. If you use LDEVs from mainframe hosts forCache LUN XP functions, you can use LDEVs belonging to CU group 0 to CU group 3. If you use LDEVsfrom open-system hosts for Cache LUN XP functions, you can use LDEVs belonging to CU group 0.

Configuration Restrictions For example, in Figure 2, the LUSE volume is composed of three LDEVs (00:01,1,000 LBAs, 00:02, 1,002 LBAs, and 00:03, 1,020 LBAs). If you want to setCache LUN XP to 500 LBAs starting from LBA number 1,020, you can setCache LUN XP to 500 LBAs starting from LBA number 20 on the second LDEV,because the first LDEV size is 1,000 LBAs.

Figure 2 Example of LBA value setting with LUSE volumes

You cannot allocate Pool-VOLs and V-VOLs for Cache LUN XP. For moreinformation, see the HP StorageWorks Snapshot XP user guide.

You cannot allocate journal volumes for Cache LUN XP.

NOTE: For more information about journal volumes, see theHP StorageWorks Continuous Access XP Journal user guide for theXP12000/XP10000/SVS200.

You cannot allocate remote command devices for Cache LUN XP.

NOTE: For more information about remote command devices, see theHP StorageWorks External Storage XP user guide.

Usage Restrictions If an LDEV is placed in cache, do not use it for BC/Continuous Access XP quickrestore operations or Auto LUN migration. These operations may swap theinternal locations of the primary and secondary volumes and cause a loss ofdata integrity.

You cannot change a Cache LUN XP extent after it is configured. To change thespecification, you must reset (release) the Cache LUN XP extent, and thenre-allocate (set) the Cache LUN XP extent.

CVS Automatic Resets In the following cases, a Cache LUN XP cache extent is deleted (resetor released)automatically:

If a fixed volume, part or all of which is assigned to Cache LUN XP, isconverted into free space by the CVS Volume to Space function.

If a custom volume, part or all of which is assigned to Cache LUN XP, isconverted into free space using the CVS Volume to Space function.

If an LDEV (or VDEV) containing fixed and custom volumes assigned to CacheLUN XP is initialized by the CVS Volume Initialize function.

Table 2 Restrictions (continued)


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You can select a CU group from the drop-down list for CU groups in the upper right on the XP Remote WebConsole main pane. After you select a CU group, you can use LDEVs only in the selected CU group. Youcannot apply or cancel Cache LUN XP settings on multiple CU groups. For more information about CUgroups, see the HP StorageWorks XP Remote Web Console user guide for XP12000/XP10000/SVS200.

NOTE: Regardless of whether you use LDEVs from mainframe or open-system hosts, you can perform theprestaging operation for all CU groups.

Cache LUN XP modesCache LUN XP has two modes:

priority mode

bind mode

Priority modePriority mode requires fewer cache resources but has performance limitations over bind mode. Prioritymode keeps all read data in cache (until you delete the extent), but all writes are destaged to disk normally(using the same algorithms as for regular, non-Cache LUN XP data). You can set the priority mode from theoperations box located on the lower-right of the Cache LUN pane.

Priority mode details

All reads following the initial read to a block will result in cache hits (100% cache read hits).

After destaging of the write block to disk, the duplicated write areas in general cache become free.

While destaging to disk, read requests to the same block are delayed until the disk operation iscompleted.

Priority mode generates write traffic to disk, whereas bind mode does not.

General cache capacity

In addition to the Cache LUN XP cache, you should set the general cache capacity according to thenumber of areas set in priority mode. This prevents a reduction in general cache performance.

If the general cache is overloaded (having very little cache space), this can result in a wait for free cachespace. This may degrade access to the general cache.

If you set up to 512 areas in Cache LUN XP, set 512 MB x 2 (1024 MB) of standard cache.

If you set 513-1024 areas in Cache LUN XP, set 1024 MB x 2 (2048 MB) of standard cache.

For OPEN-V, one slot is 66 KB, which requires 4 cache segments (16.5 KB/segment). For example,16 slots require 1,056 KB of reserved cache.

For other than OPEN-V, one slot is 49.5 KB, which requires 3 cache segments. For example, 16 slotsrequire 792 KB of reserved cache.

Bind modeBind mode keeps both read and write data in cache, eliminating disk traffic (100% read/write hits). All

data stays in cache until the extent is removed. The data stored in the Cache LUN XP cache is duplexed fordata protection, which requires additional Cache LUN XP cache capacity. If AC power is lost, data ismaintained in cache for up to 48 hours, using battery power. You can set the bind mode from theoperations box located on the lower-right of the Cache LUN pane.

Bind mode details

All reads following the initial read to a block will result in cache hits.

Duplicated write blocks are stored in cache and are never evicted.

All read or write blocks stay resident in cache until the extent is deleted.

Bind mode requires more cache because duplicated write blocks are not destaged to disk.


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Bind mode and RAID groups

To change a RAID-1, RAID-5, or RAID-6 parity groups mode from priority mode to bind mode, reset andre-allocate the affected Cache LUN XP extent. When you re-allocate, specify the greater capacity neededfor bind mode.

Pre-stagingAs mentioned before, data assigned to a Cache LUN XP cache extent becomes resident (staged) incache after it is first accessed by the host. Then, the host finds the data in cache for the second and

subsequent accesses. The pre-staging function puts data in cache before the first read. Therefore,pre-staging allows the host to find data in cache on the first access.

Specify pre-staging when you set up the cache extent. You can use this function with either priority or bindmode.

You cannot change a Cache LUN XP extent after it is configured. To change the specification, you mustreset (release) the Cache LUN XP extent, and then re-allocate (set) the Cache LUN XP extent.

Required cache size for Cache LUN XPThe required cache size for Cache LUN XP depends on the operation modes. For example, in bind mode,RAID-1 groups require twice the cache size for user data to use Cache LUN XP. However, RAID-5 or RAID-6groups require three times the cache size for user data to use Cache LUN XP.

NOTE: When external volumes are used, twice the cache size is required for user data to use CacheLUN XP.

The following sections describe the calculation procedures for each operation mode and RAID level.

Open systemsTo calculate the cache size for open systems:

1. Calculate the converted values of the starting and ending addresses.

For specified LDEVs:

a. OPEN-V

Number of LBAs = LDEV size (KB) 2

Convert LDEV size to number of LBAs

Number of slots = (Number of LBAs 512)

Round up the calculated value between the two up arrows () after the decimal point

Converted value of starting address = 0

Converted value of ending address = (Number of slots 512) - 1

b. Emulation types other than OPEN-V

Number of LBAs = LDEV size (KB) 2

Convert LDEV size to number of LBAs

Number of slots = (Number of LBAs 96)

Round up the calculated value between the two up arrows () after the decimal point


Converted value of ending address = (number of slots 96) - 1

For specified volumes:

a. OPEN-V

Starting value = (Setting value of starting address (LBA) 512)

Round down the calculated value between the two down arrows () after the decimal point

Setting value of starting address (LBA) is the value entered in the operations box on the CacheLUN pane


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Ending value = (Setting value of ending address (LBA) 512)


Setting value of ending address (LBA) is the value entered in the operations box on the CacheLUN pane

Converted value of starting address = Starting value 512

Converted value of ending address = ( (Ending value +1) 512) - 1


Starting value = (Setting value of starting address (LBA) 96)


Setting value of starting address (LBA) is the value entered in the operations box on the CacheLUN pane

Converted value of starting address = Starting value 96

Converted value of ending address = ( (Ending value +1) 96) - 1

2. Calculate the number of addresses between the starting and ending addresses calculated in step 1.

a. OPEN-V

Number of address = Converted value of ending address - Converted value of starting address + 1

Calculate the number of LBAs used by the user data


Number of LBAs = Converted value of ending address - Converted value of starting address + 1

Calculate the number of LBAs used by the user data

Number of slots = Number of LBAs 96

Convert the number of LBAs to the number of slots

Number of addresses = Number of slots 128

Convert the number of slots with 128 LBA

3. Calculate the required cache size according to the operation modes, or RAID levels, to use CacheLUN XP.

a. Bind mode

RAID-1:

Required cache size = Number of addresses (512 16) 2 1,024

Units are KB

RAID types other than RAID-1:

Required cache size = Number of addresses (512 16) 3 1,024

Units are KB

b. Priority mode

Required cache size = Number of addresses (512 16) 1,024

Units are KB

Mainframe systems

To calculate the cache size for mainframe systems:

1. Calculate the converted values of the starting and ending addresses.

For specified LDEVs:

Setting value of ending address (CC) = (( (LDEV size 15) - 1) 15)


Setting value of ending address (CC) is the value that is input to the operations box in the CacheLUN pane)

Setting value of ending address (HH) = ( (LDEV size 15) - 1) Mod15

Remainder is the setting value of ending address (HH)


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Setting value of ending address (HH) is the value entered in the operations box on the CacheLUN pane


Converted value of ending address = Setting value of ending address (CC) 15 + Setting value ofending address (HH)

Setting value of ending address (CC) and Setting value of ending address (HH) are the valuesentered in the operations box on the Cache LUN pane

For specified volumes:

Converted value of starting address = Setting value of starting address (CC) 15 + Setting value ofstarting address (HH)


Converted value of ending address = Setting value of ending address (CC) 15 + Setting value ofending address (HH)


2. Calculate the number of addresses between the starting and ending addresses calculated in step 1.

Number of addresses = Converted value of ending address - Converted value of startingaddress +1

Calculate the number of addresses of cache used by the user data3. Calculate the required cache size according to the operation modes, or RAID levels, to use Cache

LUN XP.

a. Bind mode

RAID-1:

Required cache size = (Number of addresses ( (128 (512 + 16) ) 2) 1,024

Units are KB

RAID types other than RAID-1:

Required cache size = (Number of addresses (128 (512 + 16) ) 3) 1,024

Units are KB

b. Priority modeRequired cache size = (Number of addresses (128 (512 + 16) ) ) 1,024

Units are KB

NOTE: If a RAID-5 or RAID-6 volume area is changed from priority mode to bind mode and no cache isadded, only 33 percent of the user data fits into the area previously assigned for priority mode. Theremaining 67 percent is used to save read/write data. If a RAID-1 volume area is changed from prioritymode to bind mode and no cache is added, only 50 percent of the user data fits in the area previouslyassigned for priority mode. The remaining 50 percent is used to save read/write data. Changing the modewithout cache extension requires Cache LUN XP reconfiguration.


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Starting Cache LUN XP1. Click Cache LUN in the left pane. The Cache LUN pane appears.

Figure 3 Cache LUN pane

Cache LUN paneThis pane lists the following items.

CLPR drop-down list

Use this drop-down list to select a cache logical partition (CLPR). The CLPR drop-down list displays the CLPRnumber and CLPR name.

When you select a CLPR, volumes belonging to the selected CLPR and cache information appear in the

LDEV tree.

NOTE: If you administer only one CLPR, the CLPR drop-down list is not available.

Prestaging check box

Select or clear this check box to enable or disable the pre-staging function:

If you select this check box, set the Prestaging Mode to Yes and clickApply. A non-pre-stagingoperation will be performed and then a pre-staging operation will be performed.

If you clear this check box and then clickApply, a non-pre-staging operation will be performed, but apre-staging operation will not be performed. If you select this check box later and then clickApply, onlya pre-staging operation will be performed.

When a pre-staging operation is in progress, the text Prestaging operation in progress is shown at thebottom of the Cache LUN pane. The progress is displayed in percentage.

The Prestaging check box is enabled in Modify mode and is selected by default. However, the Prestagingcheck box is disabled in either of the following conditions:

No cache

Prestaging mode is set to No for each cache


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LDEV tree

The LDEV tree displays the CU number (for example, CU 00) and LDEV number (for example, LDEV 00)available for Cache LUN XP operations in a tree. The tree uses the following icons to show the settings:

The LDEV tree does not show Auto LUN-reserved volumes because they cannot be used in Cache LUN XPoperations.

LDEV table

Information about the LDEV selected in the tree appears on a single line in the upper-right portion of thepane. It includes LDEV number, emulation type, capacity, RAID level, and VMA information.

The LDEVs capacity is shown in MB for open systems, or cylinders and tracks for mainframe systems. The

table shows the cache settings for the LDEV selected in the tree and contains the following columns: LBA(open systems only): Displays the logical block starting and ending addresses.

CC HH (mainframe systems only): Displays the cylinder and head starting and ending addresses.

Capacity: Displays the capacity of the cache extent in megabytes for open systems. Displays thecapacity of the cache extent in cylinders and tracks for mainframe systems.

Mode: Displays the mode of the cache extent. PRIO indicates priority mode, BIND indicates bind mode,and - indicates that the LDEV is not assigned to the cache.

Prestage: If this is blank, then pre-staging is not set. ON indicates that pre-staging is set.

Cache LUN XP pie chart

The text above the pie chart lists the used cache and the amount of free space left in cache. For the

XP12000/XP10000/SVS200, it also lists the total Cache LUN XP area and size that can be created in theSLPR (storage logical partition).

In the pie chart, pink indicates the amount of cache available, blue shows cache used, and yellow showsthe size of the specified cache extent.

Cache settings section

Sets the mode and area for data that will reside in the Cache LUN XP cache. Also displays the settings foran existing cache extent. This area contains the following:

Cache LUN Mode): Select the Cache LUN XP mode by clicking either Bind or Prio.

Prestaging Mode: Select the Prestaging check box (located above the LDEV tree) to perform thepre-staging operation, and then clickApply. ClickYes if pre-staging is enabled. Click No if pre-staging

is disabled. Start: The starting address for data that will reside in the cache. This is expressed as a logical block

address for open systems and as a cylinder and head address for mainframe systems.

End: The ending address for data that will reside in the cache. This is expressed as a logical blockaddress for open systems and as a cylinder and head address for mainframe systems.

NOTE: If you specify the VMA volume, and it has not been set for Cache LUN XP yet, the next LBA of LBAsfor the VMA appears in the Start box.

Select All Area: If you select this check box, all data areas in the selected LDEV will be set to CacheLUN XP cache.

Table 3 Cache LUN XP icons

Icon Description

Indicates an LDEV for which Cache LUN XP is not set.

Indicates an LDEV for which Cache LUN XP is set.

Indicates a LUSE volume (two or more LDEVs) for which Cache LUN XP is not set.


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This check box can be selected if no data areas in the selected LDEV are set to Cache LUN XP cache.This check box cannot be selected and is grayed out if some data areas in the selected LDEV are set toCache LUN XP cache. If you select the Select All Area check box, nothing will be set to the startingaddress and the ending address, and the Start and End fields remain empty.

Available Cache LUN Size): Displays the size you can set. Bind displays the size you should set for bindmode and Prio displays the size you should set for priority mode.

Multi Set / Release: Selecting this check box and then clicking Set displays the Multi Set pane, whichyou can use to make Cache LUN XP settings on more than one LDEV. Selecting this check box and thenclicking Release displays the Multi Release pane, which you can use to cancel Cache LUN XP settingson more than one LDEV.

Data that will reside in the Cache LUN XP cache is specified by the starting address in the Start fieldand the ending address in the End field. When the Select All Area check box is selected, all data areasof the selected LDEVs will be set for the Cache LUN XP.

If you cancel the settings, all the settings specified for the LDEV will be canceled.

The Multi Set / Release check box does not select and cancel an individual Cache LUN XP data areaspecified for the LDEV. You must use the Release button to cancel an individual Cache LUN XP dataarea.

If you select the VMA volume from the LDEV tree in the Cache LUN XP panel, only volumes for whichVMA is set are displayed in the Multi Set /Release panel. If you select a non-VMA volume, onlyvolumes for which VMA has not been set are displayed in the Multi Set/Release panel.

Buttons

Set: Creates a cache extent.

Release: Deletes a cache extent.

Apply: Applies the parameters to the disk array. You can then set or release other cache extents.

Cancel: Cancels the operation.

Setting (creating) a cache extent1. In the LDEV tree of the Cache LUN pane, click the CU:LDEV number of the LDEV you want to put in

cache.

The LDEV table displays Cache LUN XP information for the LDEV you selected.

2. Select an area to be made resident in the Cache LUN XP cache from one of those marked - in theMode column. The Set button is enabled. The From and To boxes display the selected areas values.

3. Click Bind or Prio to indicate the mode.

4. ClickYes or No to indicate whether to set pre-staging.

5. Complete one of the following steps:

To place all data on an LDEV into cache, go to step 6.

To place specific data from an LDEV into cache, go to step 7.

To place all data on multiple LDEVs into cache, go to step 8.

To place specific data from multiple LDEVs into cache, go to step 9.

6. To place all data on an LDEV into cache:

a. Select the Select All Area check box.

b. Clear the Multi Set / Release check box.

c. Click Set. A confirmation dialog box appears.

d. Click OKto continue. The new settings are shown in blue on the Cache LUN pane. To canceloperations, click Cancel. Go to step 10.

7. To place specific data from an LDEV into cache:

a. If the Select All Area check box is grayed out, go to the next step. If the Select All Area check box isactivated, clear the Select All Area check box.

b. Enter the starting and ending addresses (LBAs or CC HHs) of the area to be made resident in thecache.


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For open systems, Cache LUN XP identifies a logical area in units of 128 blocks for OPEN-V, and96 blocks for other than OPEN-V. For OPEN-V, if you have entered 1 as the starting logical blockaddress and a value less than 128 as the ending logical block address, Cache LUN XPautomatically changes the ending block address to 128. For other than OPEN-V, if you haveentered 1 as the starting logical block address and a value less than 96 as the ending logical blockaddress, Cache LUN XP automatically changes the ending block address to 96.

c. Clear the Multi Set / Release check box.

d. Click Set. A confirmation dialog box appears.

e. Click OKto continue. The new settings are shown in blue on the Cache LUN pane. To canceloperations, click Cancel. Go to step 10.

8. To place all data on multiple LDEVs into cache:

a. Select the Select All Area check box.

b. Select the Multi Set / Release check box.

c. Click Set. A confirmation dialog box appears.

d. Click OKto continue. The Multi Set pane appears.

Figure 4 Multi Set pane

e. In the CU drop-down list, click the CU.

f. In the table, click more than one LDEV and then click Set. The Multi Set pane closes and the newsettings are shown in blue on the Cache LUN pane. To cancel operations, click Cancel. Go tostep 10.

9. To place specific data from multiple LDEVs into cache:

a. If the Select All Area check box is grayed out, go to the next step. If the Select All Area check box isactivated, clear the Select All Area check box.

b. Enter the starting and ending addresses (LBAs or CC HHs) of the area to be made resident in thecache.

For open systems, Cache LUN XP identifies a logical area in units of 128 blocks for OPEN-V, and96 blocks for other than OPEN-V. For OPEN-V, if you have entered 1 as the starting logical blockaddress and a value less than 128 as the ending logical block address, Cache LUN XPautomatically changes the ending block address to 128. For other than OPEN-V, if you haveentered 1 as the starting logical block address and a value less than 96 as the ending logical blockaddress, Cache LUN XP automatically changes the ending block address to 96.

c. Select the Multi Set / Release check box.

d. Click Set. A confirmation dialog box appears.

e. Click OKto continue. The Multi Set pane appears.

f. In the CU drop-down list, click the CU.


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g. In the table, click more than one LDEV and then click Set. The Multi Set pane closes and the newsettings are shown in blue on the Cache LUN pane. To cancel operations, click Cancel. Go tostep 10.

10.To make data in other volumes reside in the Cache LUN XP cache, repeat the previous steps.

NOTE: You cannot use the Release button to delete the set data until you clickApply or Cancel.

11.To enable the pre-staging function, select the Prestaging check box. To disable the pre-staging function,

clear the Prestaging check box.12.If the settings are correct, clickApply. A confirmation dialog box appears.

13.Click OKto confirm. The Cache LUN XP operation begins. If prestaging was selected, the prestagingoperation will occur next. When the operation has been completed, a confirmation dialog boxappears.

14.Click OK.

Releasing (removing) a cache extent1. In the LDEV tree of the Cache LUN pane, click the CU:LDEV number of the LDEV you want to remove

from cache. The LDEV table displays Cache LUN XP information about the LDEV you selected.

2. Select an extent to be removed from the Cache LUN XP cache. The Release button is enabled.

3. Complete one of the following steps:

To remove specific data from cache, go to step 4.

To remove all data from cache, go to step 5.

4. To remove specific data from cache:

a. Click Release. A confirmation dialog box appears.

b. Click OKto continue. The new settings are shown in blue on the Cache LUN pane. To canceloperations, click Cancel. Go to step 6.

5. To remove all data from cache

a. Select the Multi Set / Release check box.

b. Click Release. A confirmation dialog box appears.

c. Click OKto continue. The Multi Release window appears.

Figure 5 Multi Release window

d. In the CU box, click the CU.


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e. In the table, click more than one LDEV and then click Release. The Multi Release pane closes andthe new settings are shown in blue on the Cache LUN pane. To cancel operations, click Cancel. Goto step 6.

6. To remove cache data for another CU:LDEV, repeat the previous steps.

7. If the deletions are correct, clickApply. A confirmation dialog box appears.

8. Click OKto confirm. The Cache LUN XP operation begins. If prestaging was selected, the prestagingoperation will occur next. When the operation has been completed, a confirmation dialog boxappears.

9. Click OK.

NOTE: Response time might be slow if you try to delete cache-resident data. This causes a conflictbecause host I/O occurs at the same time data is written to the disk drive (destaging). To avoid slowresponse time, limit the amount of data you try to delete during one operation as follows:

When the host timeout period is set to 11 seconds or more

Open system: 3 GB or less

Mainframe system: 3,000 cylinders or less

When the host timeout period is set to 10 seconds or less

Open system: 1 GB or less

Mainframe system: 1,000 cylinders or less

Changing an extents mode and pre-stagingYou cannot directly change a cache extents mode or pre-staging settings. You must delete the extent andreconfigure it with new settings.

1. Select and release (remove) the extent in the Cache LUN XP cache.

2. Remake the extent with the new mode and pre-staging settings.


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Index

Aaudience, documentation5available space17

Bbattery backup12bind mode12buttons18

Ccache extents13

about9creating18removing20size requirements10

Cache LUN pane16CLPR drop-down list16conventions

document6text symbols6

creating cache extents18CU number17custom volumes9customer support6

Ddocument

conventions6documentation, related5

Eemulation types supported9extents, cache13

about9creating18removing20size requirements10

FFirmware5

free space17

Hhelp, obtaining6, 7HP

storage web site7Subscribers choice web site6technical support6

LLDEV table17LDEV tree17

logical blocks10

Mmemory requirements9modes

settings21types of12

Ooperations9

Ppie chart17prerequisites5pre-staging

about13enabling or disabling16settings21

priority mode12

RRAID parity groups13releasing cache extents20removing cache extents20restrictions10

Ssetting cache extents18settings17size, cache

free space17requirements13

starting Cache LUN XP16Subscribers choice, HP6supported volumes9symbols in text6

Ttasks9technical support, HP6

text symbols6

Vvolumes supported9

Wweb sites

HP documentation5HP storage7HP Subscribers choice6


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24


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Figures1 Cache LUN XP operations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 Example of LBA value setting with LUSE volumes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 Cache LUN pane. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 Multi Set pane. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195 Multi Release window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20


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Tables1 Document conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 Restrictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 Cache LUN XP icons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17


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Documents

hp_CacheLUN_xp12000UG