IBM Tivoli Storage Manager, Version 7.1

UPDATE STGPOOL (Update a primary random access storage pool)

Use this command to update a random access storage pool.

Privilege class

To issue this command, you must have system privilege, unrestricted storage privilege, or restricted storage privilege for the storage pool to be updated.

Syntax

Read syntax diagramSkip visual syntax diagram
>>-UPDate STGpool--pool_name--+-----------------------------+--->
                              '-DESCription--=--description-'   

>--+----------------------------+------------------------------->
   '-ACCess--=--+-READWrite---+-'   
                +-READOnly----+     
                '-UNAVailable-'     

>--+-----------------------------------+------------------------>
   '-MAXSIze--=--+-maximum_file_size-+-'   
                 '-NOLimit-----------'     

>--+---------------------+--+---------------------------+------->
   '-CRCData--=--+-Yes-+-'  '-NEXTstgpool--=--pool_name-'   
                 '-No--'                                    

>--+---------------------+--+--------------------+-------------->
   '-HIghmig--=--percent-'  '-LOwmig--=--percent-'   

>--+-------------------+--+-----------------------+------------->
   '-CAChe--=--+-Yes-+-'  '-MIGPRocess--=--number-'   
               '-No--'                                

>--+-------------------+--+-------------------------+----------->
   '-MIGDelay--=--days-'  '-MIGContinue--=--+-Yes-+-'   
                                            '-No--'     

>--+----------------------------+------------------------------->
   '-AUTOCopy--=--+-None------+-'   
                  +-CLient----+     
                  +-MIGRation-+     
                  '-All-------'     

>--+-----------------------------------+------------------------>
   |                  .-,------------. |   
   |                  V              | |   
   '-COPYSTGpools--=----copypoolname-+-'   

>--+--------------------------+--------------------------------->
   '-COPYContinue--=--+-Yes-+-'   
                      '-No--'     

>--+-----------------------------------------------+------------>
   |                     .-,---------------------. |   
   |                     V                       | |   
   '-ACTIVEDATApools--=----active-data_pool_name-+-'   

   .-SHRED--=--0---------------.   
>--+---------------------------+-------------------------------><
   '-SHRED--=--overwrite_count-'   

Parameters

pool_name (Required)
Specifies the storage pool to update. This parameter is required.
DESCription
Specifies a description of the storage pool. This parameter is optional. The maximum length of the description is 255 characters. Enclose the description in quotation marks if it contains any blank characters. To remove an existing description, specify a null string ("").
ACCess
Specifies how client nodes and server processes (such as migration and reclamation) can access files in the storage pool. This parameter is optional. Possible values are:
READWrite
Specifies that client nodes and server processes can read and write to files stored on volumes in the storage pool.
READOnly
Specifies that client nodes can only read files from the volumes in the storage pool.

Server processes can move files within the volumes in the storage pool. However, no new writes are permitted to volumes in the storage pool from volumes outside the storage pool.

If this storage pool has been specified as a subordinate storage pool (with the NEXTSTGPOOL parameter) and is defined as readonly, the storage pool is skipped when server processes attempt to write files to the storage pool.

UNAVailable
Specifies that client nodes cannot access files stored on volumes in the storage pool.

Server processes can move files within the volumes in the storage pool and can also move or copy files from this storage pool to another storage pool. However, no new writes are permitted to volumes in the storage pool from volumes outside the storage pool.

If this storage pool has been specified as a subordinate storage pool (with the NEXTSTGPOOL parameter) and is defined as unavailable, the storage pool is skipped when server processes attempt to write files to the storage pool.

MAXSIze
Specifies the maximum size for a physical file that the server can store in the storage pool. This parameter is optional. Possible values are:
NOLimit
Specifies that there is no maximum size limit for physical files stored in the storage pool.
maximum_file_size
Limits the maximum physical file size. Specify an integer from 1 to 999999, followed by a scale factor. For example, MAXSIZE=5G specifies that the maximum file size for this storage pool is 5 gigabytes. Scale factors are:
Scale factor Meaning
K kilobyte
M megabyte
G gigabyte
T terabyte

If a file exceeds the maximum size and no pool is specified as the next storage pool in the hierarchy, the server does not store the file. If a file exceeds the maximum size and a pool is specified as the next storage pool, the server stores the file in the next storage pool that can accept the file size. If you specify the next storage pool parameter, at least one storage pool in your hierarchy should have no limit on the maximum size of a file. By having no limit on the size for at least one pool, you ensure that no matter what its size, the server can store the file.

For logical files that are part of an aggregate, the server considers the size of the aggregate to be the file size. Therefore, the server does not store logical files that are smaller than the maximum size limit if the files are part of an aggregate that is larger than the maximum size limit.

CRCData
Specifies whether a cyclic redundancy check (CRC) validates storage pool data when audit volume processing occurs on the server. This parameter is optional. The default value is NO. By setting CRCDATA to YES and scheduling an AUDIT VOLUME command you can continually ensure the integrity of data that is stored in your storage hierarchy. Possible values are:
Yes
Specifies that data is stored containing CRC information, allowing for audit volume processing to validate storage pool data. This mode impacts performance because additional overhead is required to calculate and compare CRC values between the storage pool and the server.
No
Specifies that data is stored without CRC information.
NEXTstgpool
Specifies a primary storage pool to which files are migrated. This parameter is optional.

To remove an existing storage pool from the storage hierarchy, specify a null string ("") for this value.

If this storage pool does not have a next storage pool, the server cannot migrate files from this storage pool and cannot store files that exceed the maximum size for this storage pool in another storage pool.

You cannot create a chain of storage pools that leads to an endless loop through the NEXTSTGPOOL parameter. At least one storage pool in the hierarchy must have no value specified for NEXTSTGPOOL.

If you specify a sequential access pool as the NEXTSTGPOOL, the pool can only be NATIVE or NONBLOCK dataformat.

HIghmig
Specifies that the server starts migration for this storage pool when the amount of data in the pool reaches this percentage of the pool's estimated capacity. This parameter is optional. You can specify an integer from 0 to 100.

When the storage pool exceeds the high migration threshold, the server can start migration of files by node to the next storage pool, as defined with the NEXTSTGPOOL parameter. You can specify HIGHMIG=100 to prevent migration for this storage pool.

LOwmig
Specifies that the server stops migration for this storage pool when the amount of data in the pool reaches this percentage of the pool's estimated capacity. You can specify an integer from 0 to 99 for this optional parameter.

Because migration is by node or filespace (depending upon collocation), the occupancy of the storage pool can fall below the value you specified for this parameter. You can set LOWMIG=0 to empty the storage pool.

CAChe
Specifies whether the migration process leaves a cached copy of a file in this storage pool after you migrate the file to the next storage pool. This parameter is optional. Possible values are:
Yes
Specifies that caching is enabled.
No
Specifies that caching is disabled.

Using cache might improve your ability to retrieve files, but might affect the performance of other processes.

MIGPRocess
Specifies the number of processes that are used for migrating files from this storage pool. This parameter is optional. You can specify an integer from 1 to 999.

During migration, these processes are run in parallel to provide the potential for improved migration rates.

Tips:
  • The number of migration processes is dependent upon the following parameters:
    • The setting of the MIGPROCESS parameter
    • The collocation setting of the next pool
    • The number of nodes or the number of collocation groups with data in the storage pool that is being migrated
    For this example, MIGPROCESS =6, the next pool COLLOCATE parameter is NODE, but there are only two nodes with data on the storage pool. Migration processing consists of only two processes, not six. If the COLLOCATE parameter is GROUP group and both nodes are in the same group, migration processing consists of only one process. If the COLLOCATE parameter is NO or FILESPACE group, and each node has two file spaces with backup data, then migration processing consists of only four processes.
  • When you specify this parameter, consider whether the simultaneous-write function is enabled for server data migration. Each migration process requires a mount point and a drive for each copy storage pool and active-data pool that is defined to the target storage pool.
MIGDelay
Specifies the minimum number of days a file must remain in a storage pool before it becomes eligible for migration. To calculate a value to compare to the specified MIGDELAY value, the server counts the number of days that the file was in the storage pool and the number of days, if any, since the file was retrieved by a client. The lesser of the two values is compared to the specified MIGDELAY value. For example, if all the following conditions are true, a file is not migrated:
  • A file was in a storage pool for five days.
  • The file was accessed by a client within the past three days.
  • The value that is specified for the MIGDELAY parameter is four days.

This parameter is optional. You can specify an integer from 0 to 9999.

If you want the server to count the number of days that are based only on when a file was stored and not when it was retrieved, use the NORETRIEVEDATE server option.

MIGContinue
Specifies whether you allow the server to migrate files that do not satisfy the migration delay time. This parameter is optional.

Because you can require that files remain in the storage pool for a minimum number of days, the server may migrate all eligible files to the next storage pool yet not meet the low migration threshold. This parameter allows you to specify whether the server is allowed to continue the migration process by migrating files that do not satisfy the migration delay time.

Possible values are:
Yes
Specifies that, when necessary to meet the low migration threshold, the server continues to migrate files that do not satisfy the migration delay time.

If you allow more than one migration process for the storage pool, some files that do not satisfy the migration delay time may be migrated unnecessarily. As one process migrates files that satisfy the migration delay time, a second process could begin migrating files that do not satisfy the migration delay time to meet the low migration threshold. The first process that is still migrating files that satisfy the migration delay time might have, by itself, caused the low migration threshold to be met.

No
Specifies that the server stops migration when no eligible files remain to be migrated, even before reaching the low migration threshold. The server does not migrate files unless the files satisfy the migration delay time.
AUTOCopy
Specifies when Tivoli® Storage Manager writes data simultaneously to copy storage pools and active-data pools. This parameter affects the following operations:
  • Client store sessions
  • Server import processes
  • Server data-migration processes

If an error occurs while data is being simultaneously written to a copy storage pool or active-data pool during a migration process, the server stops writing to the failing storage pools for the remainder of the process. However, the server continues to store files into the primary storage pool and any remaining copy storage pools or active-data pools. These pools remain active for the duration of the migration process. Copy storage pools are specified using the COPYSTGPOOLS parameter. Active-data pools are specified using the ACTIVEDATAPOOLS parameter.

Possible values are:
None
Specifies that the simultaneous-write function is disabled.
CLient
Specifies that data is written simultaneously to copy storage pools and active-data pools during client store sessions or server import processes. During server import processes, data is written simultaneously to only copy storage pools. Data is not written to active-data pools during server import processes.
MIGRation
Specifies that data is written simultaneously to copy storage pools and active-data pools only during migration to this storage pool. During server data-migration processes, data is written simultaneously to copy storage pools and active-data pools only if the data does not exist in those pools. Nodes whose data is being migrated must be in a domain associated with an active-data pool. If the nodes are not in a domain associated with an active pool, the data cannot be written to the pool.
All
Specifies that data is written simultaneously to copy storage pools and active-data pools during client store sessions, server import processes, or server data-migration processes. Specifying this value ensures that data is written simultaneously whenever this pool is a target for any of the eligible operations.
COPYSTGpools
Specifies the names of copy storage pools where the server writes data simultaneously. You can specify a maximum of three copy pool names that are separated by commas. Spaces between the names of the copy pools are not permitted. To add or remove one or more copy storage pools, specify the pool name or names that you want to include in the updated list. For example, if the existing copy pool list includes COPY1 and COPY2 and you want to add COPY3, specify COPYSTGPOOLS=COPY1,COPY2,COPY3. To remove all existing copy storage pools that are associated with the primary storage pool, specify a null string ("") for the value (for example, COPYSTGPOOLS="").

When specifying a value for the COPYSTGPOOLS parameter, you can also specify a value for the COPYCONTINUE parameter. For more information, see the COPYCONTINUE parameter.

The combined total number of storage pools that are specified in the COPYSGTPOOLS and ACTIVEDATAPOOLS parameters cannot exceed three.

When a data storage operation switches from a primary storage pool to a next storage pool, the next storage pool inherits the list of copy storage pools and the COPYCONTINUE value from the primary storage pool. The primary storage pool is specified by the copy group of the management class that is bound to the data.

The server can write data simultaneously to copy storage pools for the following operations:
  • Backup and archive operations by Tivoli Storage Manager backup-archive clients or application clients using the Tivoli Storage Manager API
  • Migration operations by Tivoli Storage Manager for Space Management clients
  • Import operations that involve copying exported file data from external media to a primary storage pool associated with a copy storage pool list
Restrictions: The simultaneous-write function is not supported for the following store operations:
  • When the operation is using LAN-free data movement. Simultaneous-write operations take precedence over LAN-free operations, causing the operations to go over the LAN. However, the simultaneous-write configuration is accepted.
  • NAS backup operations. If the primary storage pool specified in the DESTINATION or TOCDESTINATION in the copy group of the management class has copy storage pools defined, the copy storage pools are ignored and the data is stored into the primary storage pool only.
Attention: The function that is provided by the COPYSTGPOOLS parameter is not intended to replace the BACKUP STGPOOL command. If you use the COPYSTGPOOLS parameter, continue to use the BACKUP STGPOOL command to ensure that the copy storage pools are complete copies of the primary storage pool. There are cases when a copy might not be created. For more information, see the COPYCONTINUE parameter description.
COPYContinue
Specifies how the server reacts to a copy storage pool write failure for any of the copy storage pools that are listed in the COPYSTGPOOLS parameter. This parameter is optional. When you specify the COPYCONTINUE parameter, either a COPYSTGPOOLS list must exist or the COPYSTGPOOLS parameter must also be specified.
Possible values are:
Yes
If the COPYCONTINUE parameter is set to YES, the server will stop writing to the failing copy pools for the remainder of the session, but continue storing files into the primary pool and any remaining copy pools. The copy storage pool list is active only for the life of the client session and applies to all the primary storage pools in a particular storage pool hierarchy.
No
If the COPYCONTINUE parameter is set to NO, the server will fail the current transaction and discontinue the store operation.
Restrictions:
  • The setting of the COPYCONTINUE parameter does not affect active-data pools. If a write failure occurs for any of the active-data pools, the server stops writing to the failing active-data pool for the remainder of the session, but continues storing files into the primary pool and any remaining active-data pools and copy storage pools. The active-data pool list is active only for the life of the session and applies to all the primary storage pools in a particular storage pool hierarchy.
  • The setting of the COPYCONTINUE parameter does not affect the simultaneous-write function during server import. If data is being written simultaneously and a write failure occurs to the primary storage pool or any copy storage pool, the server import process fails.
  • The setting of the COPYCONTINUE parameter does not affect the simultaneous-write function during server data migration. If data is being written simultaneously and a write failure occurs to any copy storage pool or active-data pool, the failing storage pool is removed and the data migration process continues. Write failures to the primary storage pool cause the migration process to fail.
ACTIVEDATApools
Specifies the names of active-data pools where the server writes data simultaneously during a client backup operation. The ACTIVEDATAPOOLS parameter is optional. Spaces between the names of the active-data pools are not permitted.

The combined total number of storage pools that are specified in the COPYSGTPOOLS and ACTIVEDATAPOOLS parameters cannot exceed three.

When a data storage operation switches from a primary storage pool to a next storage pool, the next storage pool inherits the list of active-data pools from the destination storage pool specified in the copy group. The primary storage pool is specified by the copy group of the management class that is bound to the data.

The server can write data simultaneously to active-data pools only during backup operations by Tivoli Storage Manager backup-archive clients or application clients that use the Tivoli Storage Manager API.
Restrictions:
  1. This parameter is available only to primary storage pools that use NATIVE or NONBLOCK data format. This parameter is not available for storage pools that use the following data formats:
    • NETAPPDUMP
    • CELERRADUMP
    • NDMPDUMP
  2. Writing data simultaneously to active-data pools is not supported when the operation is using LAN-free data movement. Simultaneous-write operations take precedence over LAN-free operations, causing the operations to go over the LAN. However, the simultaneous-write configuration is accepted.
  3. Simultaneous-write operations are not supported when a NAS backup operation is writing a TOC file. If the primary storage pool specified in the TOCDESTINATION in the copy group of the management class has active-data pools defined, the active-data pools are ignored and the data is stored into the primary storage pool only.
  4. You cannot use the simultaneous-write function with Centera storage devices.
  5. Data being imported will not be stored in active-data pools. After an import operation, use the COPY ACTIVEDATA command to store the imported data in an active-data pool.
Attention: The function that is provided by the ACTIVEDATAPOOLS parameter is not intended to replace the COPY ACTIVEDATA command. If you use the ACTIVEDATAPOOLS parameter, use the COPY ACTIVEDATA command to ensure that the active-data pools contain all active data of the primary storage pool.
SHRED
Specifies whether data is physically overwritten when it is deleted. This parameter is optional. You can specify an integer from 0 to 10.

If you specify a value of 0, the Tivoli Storage Manager server deletes the data from the database. However, the storage used to contain the data will not be overwritten, and the data will still exist in storage until that storage is reused for other data. It might be possible to discover and reconstruct the data after it has been deleted. Changing the value (for example, resetting it to 0) will not affect data that was deleted and is waiting to be overwritten.

If you specify a value greater than 0, the Tivoli Storage Manager server deletes the data both logically and physically. The server overwrites the storage used to contain the data the specified number of times. This prevents any attempts to discover and reconstruct the data after it has been deleted.

To ensure that all copies of the data are shredded, specify a SHRED value greater than 0 for the storage pool specified in the NEXTSTGPOOL parameter, and do not specify either the COPYSTGPOOLS or ACTIVEDATAPOOLS. Specifying relatively high values for the overwrite count will generally improve the level of security, but can affect performance adversely.

Overwriting of deleted data is performed asynchronously after the delete operation is complete. Therefore, the space occupied by the deleted data remains occupied for some period of time and will not be available as free space for new data.

A SHRED value greater than zero cannot be used if the value of the CACHE parameter is YES. If you want to enable shredding for an existing storage pool for which caching is already enabled, you must change the value of the CACHE parameter to NO. Existing cached files remain in storage so that subsequent retrieval requests can be satisfied quickly. If space is needed to store new data, the existing cached files are erased so that the space they occupied can be used for the new data. The existing cached files will not be shredded when they are erased.
Important: After an export operation finishes identifying files for export, any changes to the storage pool SHRED value is ignored. An export operation that is suspended retains the original SHRED value throughout the operation. You might want to consider canceling your export operation if changes to the storage pool SHRED value jeopardize the operation. You can reissue the export command after any needed cleanup.

Example: Update a random access storage pool to permit caching

Update the random access storage pool named BACKUPPOOL to permit caching when the server migrates files to the next storage pool.
update stgpool backuppool cache=yes
Parent topic: UPDATE STGPOOL (Update a storage pool)

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