IBM Tivoli Storage Manager, Version 7.1

EXTEND DBSPACE (Increase space for the database)

Use this command to increase space for the database by adding directories for the database to use.

Privilege class

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

When you issue the EXTEND DBSPACE command, directories are added to the database. With the default parameter settings, data is redistributed across all database directories, and storage space is reclaimed. This action improves parallel I/O performance and makes the new directory space available for immediate use.

If you do not want to redistribute data when you add new directories, you can specify RECLAIMSTORAGE=NO. If you specify No for this parameter, all space in existing directories is filled before new directories are used. You can redistribute data and reclaim space later, but you must complete the manual procedure for this task by using DB2 commands.

Restriction: Redistribution of data and reclaiming of space as part of an operation to extend database space only works with DB2 version 9.7 or later table spaces, which are created when you format a new Tivoli® Storage Manager version 6.2 or later server. If you upgraded or restored your Tivoli Storage Manager server from version 6.1, you cannot redistribute data or reclaim space. You must issue the EXTEND DBSPACE command with RECLAIMSTORAGE=NO.

Important: The redistribution process uses considerable system resources, so ensure that you plan ahead when you want to add space to the database. Review the following guidelines:

Complete the process when the server is not handling a heavy workload.
The time that is required to redistribute data and reclaim space might vary and is affected by factors such as the file system layout, the ratio of new paths to existing storage paths, server hardware, and concurrent operations. To get a rough estimate, you can try the operation with a small Tivoli Storage Manager database on a lab system. Use your results as a reference to estimate the time that is required for the procedure.
Do not interrupt the redistribution process. If you try to stop it, for example, by halting the process that is completing the work, you must stop and restart the DB2® server. When the server is restarted, it will go into crash recovery mode, which takes several minutes, after which the redistribution process resumes.

When you add directories to the database, ensure that you follow best practices. For more information, see Configuring the server database directories for optimal performance.

After an operation to extend the database space is complete, halt and restart the server to fully use the new directories. If the existing database directories are nearly full when a new directory is added, the server might encounter an out of space condition (reported in the db2diag.log). This condition should be corrected by halting and restarting the server.

Syntax


                   .-,------------.   
                   V              |   
>>-EXTend DBSpace----db_directory-+----------------------------->

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

Parameters

db_directory (Required)

Specifies the directories for database storage. The directories must be empty and accessible by the user ID of the database manager. A directory name must be a fully qualified name and cannot exceed 175 characters in length. Enclose the name in quotation marks if it contains embedded blanks, an equal sign, or other special characters. If you are specifying a list of directories for database storage, the maximum length of the list can be 1400 characters.

Restriction: You cannot specify Universal Naming Convention (UNC) paths.

REClaimstorage

Specifies whether data is redistributed across newly created database directories and space is reclaimed from the old storage paths. This parameter is optional. The default value is Yes.

Unless you specify WAIT=YES, the operation is performed as a background process.

Yes: Specifies that data is redistributed so new directories are available for immediate use.
Important: The redistribution process uses considerable system resources so ensure that you plan ahead.

After the process starts, messages are issued to inform you about the progress. You can use the QUERY PROCESS command to monitor the operation. To cancel the process, you can use the CANCEL PROCESS command, but if a data redistribution operation is in progress, it will complete before the process is stopped.
No: Specifies that data is not redistributed across database directories and storage space is not reclaimed when space is added for the database.

Wait

Specifies whether this command is processed in the background or foreground.

No: Specifies background processing. This is the default.
Yes: Specifies foreground processing.
You cannot specify YES from the server console.

Example: Add directories to the storage space for the database, redistribute data, and reclaim storage

Add two directories (/tsm_db/stg1 and tsm_db/stg2) under the /tsm_db directory to the storage space for the database. Issue the command:

extend dbspace /tsm_db/stg1,/tsm_db/stg2

Example: Add drives to the storage space for the database, redistribute data, and reclaim storage

Add drives D and E to the storage space for the database. Issue the command:

extend dbspace D:,E:

Related commands

Table 1. Commands related to EXTEND DBSPACE
Command	Description
DSMSERV EXTEND DBSPACE	Adds directories to increase space for use by the database.
QUERY DB	Displays allocation information about the database.
QUERY DBSPACE	Displays information about the storage space defined for the database.

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