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Tivoli Storage Manager for Macintosh Backup-Archive Client Installation and User's Guide

Resourceutilization

System Administrator

Use the resourceutilization option in your TSM System Preferences file within a server stanza to regulate the level of resources the Tivoli Storage Manager server and client can use during processing.

Regulating Backup and Archive Sessions

When you request a backup or archive, the client can use more than one session to the server. The default is to use a maximum of two sessions; one to query the server and one to send file data. The client can use only one server session if you specify a resourceutilization setting of 1. The client is also restricted to a single session if a user who is not authorized invokes a Macintosh client with passwordaccess=generate specified.

A client can use more than the default number of sessions when connecting to a server that is Version 3.7 or higher. For example, resourceutilization=10 permits up to eight sessions with the server. Multiple sessions may be used for querying the server and sending file data.

Multiple query sessions are used when you specify multiple volumes with a backup or archive command. For example, if you enter:

inc filespaceA filespaceB

and you specify resourceutilization=5, the client may start a second session to query files on file space B. Whether or not the second session starts depends on how long it takes to query the server about files backed up on file space A. The client may also try to read data from the file system and send it to the server on multiple sessions.

Regulating Restore Sessions

When you request a restore, the default is to use a maximum of one session, based on how many tapes the requested data is stored on, how many tape drives are available, and the maximum number of mount points allowed for the node.

Notes:

  1. If all of the files are on disk, only one session is used. There is no multi-session for a pure disk storage pool restore. However, if you are performing a restore in which the files reside on 4 tapes and some on disk, you could use up to 5 sessions during the restore.

  2. The Tivoli Storage Manager server can set the maximum number of mount points a node can use on the server using the MAXNUMMP parameter.

For example, if the data you want to restore is on 5 different tape volumes, the maximum number of mount points is 5 for your node, and resourceutilization is set to 3, then 3 sessions will be used for the restore. If you increase the resourceutilization setting to 5, then 5 sessions will be used for the restore. There is a 1 to 1 relationship to the number of restore sessions allowed and the resourceutilization setting. Multiple restore sessions are only allowed for no query restore operations.

Considerations

The following factors can affect the throughput of multiple sessions:

Potentially undesirable aspects of running multiple sessions include:

Notes:

  1. The Tivoli Storage Manager Client API does not support this option.
  2. The server can also define this option.

Preferences File

Place this option in the TSM System Preferences file within a server stanza.

Syntax

>>-RESOURceutilization- number---------------------------------><
 
 

Parameters

number
Specifies the level of resources the Tivoli Storage Manager server and client can use during processing. The range of values that you can specify is 1 through 10.

Examples

TSM System Preferences:
resourceutilization 8


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