IBM Tivoli Storage Manager, Version 7.1

DEFINE SPACETRIGGER (Define the space trigger)

Use this command to define settings for triggers that determine when and how the server prepares extra space when predetermined thresholds are exceeded in storage pools that use FILE and DISK device classes. Space triggers are not enabled for storage pools with a parameter RECLAMATIONTYPE=SNAPLOCK.

Tivoli® Storage Manager allocates more space when space utilization reaches a specified value. After allocating more space, Tivoli Storage Manager either adds the space to the specified pool (random-access or sequential-access disk).

Important: Space trigger functions and storage pool space calculations take into account the space remaining in each directory. An inaccurate calculation can result in a failure to expand the space available in a storage pool. Failure to expand space in a storage pool is one of the conditions that can cause a trigger to become disabled.

For example, if you specify multiple directories for a device class and the directories reside in the same file system, the server calculates space by adding values representing the space remaining in each directory. These space calculations are inaccurate. Rather than choosing a storage pool with sufficient space for an operation, the server might choose the directory that is specified for the device class and run out of space prematurely.

To prevent possible problems and ensure an accurate calculation, you associate each directory with a separate file system. If a trigger becomes disabled because the space in a storage pool could not be expanded, you can re-enable the trigger by specifying the following command: update spacetrigger stg. No further changes are required to the space trigger.

Privilege class

To issue this command, you must have system privilege or unrestricted storage privilege.

Syntax


                                 .-Fullpct--=--80------.   
>>-DEFine SPACETrigger----STG----+---------------------+-------->
                                 '-Fullpct--=--percent-'   

   .-SPACEexpansion--=--20------.   
>--+----------------------------+------------------------------->
   '-SPACEexpansion--=--percent-'   

>--+----------------------------+------------------------------->
   '-EXPansionprefix--=--prefix-'   

>--+-------------------------------+---------------------------><
   '-STGPOOL--=--storage_pool_name-'

Parameters

STG

Specifies a storage pool space trigger.

Fullpct

This parameter specifies the utilization percentage of the storage pool. This parameter is optional. Specify an integer value 0 - 99. The default is 80. A value of zero (0) disables the space trigger. When this value is exceeded, the space trigger creates new volumes. Exceeding the threshold might not cause new volumes to be created until the next space request is made.

You can determine storage pool utilization by issuing the QUERY STGPOOL command with FORMAT=DETAILED. The percentage of storage pool utilization is displayed in the field "Space Trigger Util." The calculation for this percentage does not include potential scratch volumes. The calculation for the percentage utilization that is used for migration and reclamation, however, does include potential scratch volumes.

SPACEexpansion

For sequential-access FILE-type storage pools, this parameter is used in determining the number of additional volumes that are created in the storage pool. This parameter is optional. The default is 20. Volumes are created using the MAXCAPACITY value from the storage pool's device class. For random-access DISK storage pools, the space trigger creates a single volume using the EXPANSIONPREFIX.

EXPansionprefix

For random-access DISK storage-pools, this parameter specifies the prefix that the server uses to create new storage pool files. This parameter is optional and applies only to random-access DISK device classes. The default prefix is the server installation path.

The prefix can include one or more directory separator characters, for example:

AIX operating systems

/opt/tivoli/tsm/server/bin/

c:\program files\tivoli\tsm\

AIX operating systems HP-UX operating systems Linux operating systems Sun Solaris operating systems You can specify up to 250 characters. If you specify an invalid prefix, automatic expansion can fail.

Windows operating systems You can specify up to 200 characters. If you specify an invalid prefix, automatic expansion can fail. If the server is running as a Windows service, the default prefix is the c:\wnnt\system32 directory.

This parameter is not valid for space triggers for sequential-access FILE storage pools. Prefixes are obtained from the directories that are specified with the associated device class.

STGPOOL

Specifies the storage pool that is associated with this space trigger. This parameter is optional for storage pool space triggers. If you specify the STG parameter but not the STGPOOL parameter, one space trigger is created that applies to all random-access DISK and sequential-access FILE storage pools that do not have a specific space trigger.

This parameter does not apply to storage pools with the parameter RECLAMATIONTYPE=SNAPLOCK.

Example: Define a space trigger to increase storage pool space 25 percent

Set up a storage pool space trigger for increasing the amount of space in a storage pool by 25 percent when it is filled to 80 percent utilization of existing volumes. Space is created in the directories associated with the device class.

define spacetrigger stg spaceexpansion=25 stgpool=file

Example: Define a space trigger to increase storage pool space 40 percent

Set up a space trigger for the WINPOOL1 storage pool to increase the amount of space in the storage pool by 40 percent when it is filled to 80 percent utilization of existing volumes.

define spacetrigger stg spaceexpansion=40 stgpool=winpool1

Related commands

Table 1. Commands related to DEFINE SPACETRIGGER
Command	Description
DEFINE VOLUME	Assigns a volume to be used for storage within a specified storage pool.
DELETE SPACETRIGGER	Deletes the storage pool space trigger.
QUERY SPACETRIGGER	Displays information about a storage pool space trigger.
UPDATE SPACETRIGGER	Changes attributes of storage pool space trigger.

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