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Administrator's Guide


Notes on Operations

The following sections summarize choices and procedures you need to be aware of when operating tape devices for TSM. The sections give pointers to additional information.

Collocation

Collocation is a process by which the server attempts to keep all files belonging to a client node or a client file space on a minimal number of sequential access storage volumes. You set collocation on or off for each sequential access storage pool, which includes tapes. By using collocation, you can reduce the number of volume mounts required when users restore, retrieve, or recall many files. However, when collocation is on, more volume mounts are required when clients store files.

To understand the advantages and disadvantages of collocation, see Keeping a Client's Files Together: Collocation and How Collocation Affects Reclamation.

Maintaining the Volume Inventory

You can maintain your tape volume inventory by performing the following tasks:

Sending Volumes Offsite: TSM expects to be able to access all volumes it knows about. You should not remove volumes from the site (preventing TSM access) unless the volumes are in a copy storage pool and you inform TSM that the volumes are offsite. For example, TSM tries to fill up tape volumes. If a volume containing client backups is only partially full, TSM later requests that volume be mounted to store additional data. If the volume cannot be mounted, an error occurs. To send data on volumes offsite for safekeeping, use a copy storage pool to make copies that can then be sent offsite and tracked by TSM. For more information, see Backing Up Storage Pools.

Reusing Tapes in Storage Pools

To reuse tapes in TSM storage pools, you must do two things:

Expiration Processing of Client Files

Expiration processing deletes from the TSM database any client files that are no longer valid according to the policies you have set. For example, a file is deleted by expiration processing if four backup versions exist, and only three versions are allowed in the backup policy for the file. Expiration processing frees space in your storage pools.

You can run expiration processing by using one or both of the following methods:

Reclamation

You can have TSM reclaim volumes that pass a reclamation threshold, a percentage of unused space on the volume. The reclamation threshold is set for each storage pool. See Reclaiming Space in Sequential Access Storage Pools.

For a storage pool associated with a device class that has more than one mount point, the reclaimed data is moved to other volumes in the same storage pool. For a storage pool associated with a device class that has only one mount point, the reclaimed data is moved to volumes in another storage pool that you must define, called a reclamation storage pool. See Reclaiming Volumes in a Storage Pool with One Drive.

Reusing Volumes Used for Database Backups and Export Operations

When you back up the database or export server information, TSM records information about the volumes used for these operations in the volume history file. TSM will not allow you to reuse these volumes until you delete the volume information from the volume history file. To reuse volumes that have previously been used for database backup or export, use the DELETE VOLHISTORY command. For information about the volume history file, see Saving the Volume History File.

Note:
If your server is licensed for the DRM feature, the volume information is automatically deleted during MOVE DRMEDIA command processing. For additional information about DRM, see Chapter 21, Using Tivoli Disaster Recovery Manager.


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