Performance Considerations

When you perform a backup or restore of a DB2 database, you provide "number of sessions" as a parameter. The following rules apply and should be considered when determining the number of sessions:

  • The behavior of the product is affected by the settings of BEX_MAXTASKS and BEX_MAXDRIVES in the sbt11cfg.BEX file.

  • If BEX_MAXTASKS is set greater than one, the DB2 sessions might interleave on tape. This may help performance for backups if without it the tapes are not streaming the data, but it may also degrade restore performance.

  • Each DB2 session becomes a task and is assigned to a drive until the product of BEX_MAXTASKS x BEX_MAXDRIVES is reached.

  • The remaining tasks are in pending state. When a task is completed, one of the pending tasks becomes a running task and takes the place of the completed one.

Last updated