IBM Tivoli Storage Manager, Version 7.1

MIGRATE STGPOOL (Migrate storage pool to next storage pool)

Use this command to migrate files from one storage pool to the next storage pool in the storage hierarchy.

This command can only be used with primary storage pools. The storage pool data format cannot be NETAPPDUMP, CELERRADUMP, or NDMPDUMP. Data cannot be migrated into or out of storage pools that are defined with a CENTERA device class.

Only one migration or reclamation process for a given storage pool is allowed at any given time. If a migration or reclamation process is already running for the storage pool, you cannot start another migration process for the storage pool.

You should only use this command if you are not going to use automatic migration for the storage pool. To prevent automatic migration from running, set the HIGHMIG attribute of the storage pool definition to 100.

If you use this command to start a migration process, but the storage pool does not have a next storage pool identified in the hierarchy, a reclamation process is triggered for the source storage pool. To prevent the reclamation process, define the next storage pool in the hierarchy. For details, see Setting up a storage pool hierarchy. Then, start the migration process.

The MIGRATE STGPOOL command honors the values of the following parameters on the DEFINE STGPOOL and UPDATE STGPOOL commands:

MIGPROCESS
MIGDELAY
MIGCONTINUE
NEXTPOOL
LOWMIG
Tip: You can override the value of the LOWMIG parameter on DEFINE STGPOOL and UPDATE STGPOOL by specifying a value for the LOWMIG parameter on the MIGRATE STGPOOL command.

The MIGRATE STGPOOL command ignores the value of the HIGHMIG parameter of the storage pool definition. Migration occurs regardless of the value of the HIGHMIG parameter.

This command creates one or more migration processes that can be canceled with the CANCEL PROCESS command. The number of processes is limited by the MIGPROCESS attribute of the storage pool definition. To display information about background processes, use the QUERY PROCESS command.

Remember: Migrating data from a primary storage pool that is set up for data deduplication to another primary storage pool that is also set up for data deduplication removes duplicate data.

Privilege class

To issue this command, you must have system privilege, unrestricted storage privilege, or restricted storage privilege for both the storage pool from which the files are to be migrated and the next storage pool to which files are to be migrated.

Syntax


>>-MIGrate STGpool--pool_name--+-------------------+------------>
                               '-LOwmig--=--number-'   

                             .-REClaim--=--No------.   
>--+----------------------+--+---------------------+------------>
   '-DUration--=--minutes-'  '-REClaim--=--+-No--+-'   
                                           '-Yes-'     

   .-Wait--=--No------.   
>--+------------------+----------------------------------------><
   '-Wait--=--+-No--+-'   
              '-Yes-'

Parameters

pool_name (Required)

Specifies the primary storage pool from which files are to be migrated.

DUration

Specifies the maximum number of minutes the migration runs before being automatically canceled. When the specified number of minutes elapses, the server will automatically cancel all migration processes for this storage pool. As soon as the processes recognize the automatic cancellation, they end. As a result, the migration might run longer than the value you specified for this parameter. You can specify a number from 1 to 9999. This parameter is optional. If not specified, the server will stop only after the low migration threshold is reached.

LOwmig

For random-access and sequential-access disk storage pools, specifies that migration should stop when the amount of data in the pool is at or below this percentage of the pool's estimated capacity. This parameter is optional.

The calculation for sequential-access disk storage pools includes the capacity of all the scratch volumes that are specified for the pool. Because migration is by node or filespace, depending upon collocation, the occupancy of the storage pool can fall below the value that you specified for this parameter. To empty the storage pool, set LOWMIG=0. For other types of sequential-access storage pools, the server stops migration when the ratio of volumes containing data to the total number of volumes in the storage pool is at or below this percentage. The total number of volumes includes the maximum number of scratch volumes. You can specify a number from 0 to 99 for this optional parameter. The default value is the LOWMIG attribute of the storage pool definition.

REClaim

Specifies whether reclamation is attempted for the storage pool before completing the migration. This parameter can only be specified for a sequential-access storage pool. This parameter is optional. The default is No. Possible values are:

No: Specifies that the server will not attempt a reclamation before starting the migration.
Yes: Specifies that the server will attempt reclamation before starting the migration. Any volumes in the storage pool that meet the reclamation threshold as specified by the RECLAIM attribute of the storage pool definition will be reclaimed before completing the migration. If no volumes meet the reclamation threshold or if, after reclamation, the LOWMIG threshold has not been reached, the server will begin the migration. Before reclaiming space for storage pools defined with RECLAMATIONTYPE=SNAPLOCK, the server deletes all empty WORM FILE volumes during reclamation processing that have exceeded their reclaim period.

Wait

Specifies whether to wait for the server to complete processing this command in the foreground. This parameter is optional. This default is No. Possible values are:

No

Specifies that the server processes this command in the background.

You can continue with other tasks while the command is being processed. Messages that are created from the background process are displayed either in the activity log or the server console, depending on where messages are logged.

To cancel a background process, use the CANCEL PROCESS command. If you cancel this process, some files may have already been migrated before the cancellation.

Yes

Specifies that the server processes this command in the foreground. The operation must complete before you can continue with other tasks. The server then displays the output messages to the administrative client when the operation completes. Messages are also displayed either in the activity log or the server console, or both, depending on where the messages are logged.

Note: You cannot specify WAIT=YES from the server console.

Example: Migrate a storage pool to the next storage pool

Migrate data from the storage pool named BACKUPPOOL to the next storage pool. Specify that the server should end the migration as soon as possible after 90 minutes.

migrate stgpool backuppool duration=90

Related commands

Table 1. Commands related to MIGRATE STGPOOL
Command	Description
CANCEL PROCESS	Cancels a background server process.
QUERY PROCESS	Displays information about background process.
QUERY STGPOOL	Displays information about storage pools.
RECLAIM STGPOOL	Performs reclamation for the storage pool.

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