IBM Tivoli Storage Manager Version 5.3 Technical Workshop Presentation Guide

Chapter 2. Server enhancements 23

2.7 Disk device enhancements

Figure 2-13 Disk device enhancements

Disk-only backup has been enhanced to take advantage of the inexpensive disk storage

currently available on the market. These improvements to sequential-access FILE device type

and random-access DISK device class storage include:

򐂰 The ability to create large, sequential-access FILE-type storage pools using a single FILE

device-class definition that specifies two or more directories

򐂰 The ability to create and format FILE device type or DISK device type volumes in a single

step

򐂰 The ability to use enhanced space trigger functionality to automatically allocate space for

private volumes in sequential-access FILE device type and random-access DISK device

class storage pools

This reduces the potential for disk fragmentation and maintenance overhead.

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Server enhancements

•Disk device enhancements

–Less expensive disk and longer disk retention requirements are

driving large disk storage pools at many installations.

–Device types DISK and FILE are capable of providing space

triggers for automatic allocation of storage pool space, which

can result in increased efficiency of disk storage pools.

24 IBM Tivoli Storage Manager Version 5.3 Technical Workshop Presentation Guide

Figure 2-14 Enhancements for sequential-access disk storage pools

The following commands have changed:

򐂰 DEFINE DBCOPY

򐂰 DEFINE DEVCLASS—FILE

򐂰 DEFINE LOGCOPY

򐂰 DEFINE PATH (when the destination is a drive)

򐂰 DEFINE SPACETRIGGER

򐂰 DEFINE VOLUME

򐂰 UPDATE DEVCLASS—FILE

򐂰 UPDATE PATH (when the destination is a drive)

There are several other new or changed options for the DEFINE DEVCLASS—FILE

command. One is the DIRECTORY option, which now enables you to define several

directories for the files used in this device class. Since the files are created as needed, they

are created in the directories that are defined.

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Server enhancements

•Enhancements for sequential-access disk pools

- Allow storage pools to span multiple file systems

- Support parallel migration from sequential-access pools

- Minimize fragmentation of file volumes to improve performance

- Exploit direct I/O on supported platforms

- Remove mount point limitations

Chapter 2. Server enhancements 25

Figure 2-15 Disk device enhancements overview

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Server enhancements

Reuse delay avoids auditMust audit all volumesDatabase regression

Yes (beginning in 5.3)YesPools can span file systems

Optimized for efficiencyMust check every fileStorage pool backup

Yes (beginning in 5.3)YesParallel migration processes

By volumeBy node and file spaceMigration/stg pool backup

YesNoCan be used for copy pools

Yes, via SANergyNot supportedTarget for LAN-free backup

One session per volumeOne session for all volumesMulti-session client restore

Not supportedYesConcurrent volume access

During volume reclamationNot supportedAggregate reconstruction

Not applicableWhen space is neededRecovery of cache space

When volume is reclaimedWhen file is deleted/movedSpace recovery (no cache)

Not supportedOptional (backup overhead)TSM caching

Sequential within file volumeRandom 4 KB blocksSpace allocation/tracking

Sequential-accessRandom-access

Disk device enhancements overview