Understanding multiple session support

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You can use multiple tape drives simultaneously to increase the transfer rate to or from the IBM Storage Protect™ server. Several backup sessions access the database in parallel on the database server, and the data is written simultaneously to several tape drives.

Figure 1. Parallel (multiple) sessions

This graphic shows the principle of multiple sessions. Several backup sessions access the database in parallel on the database server. The data is transferred in parallel through the network and the IBM Storage Protect backup server writes the data simultaneously to several tape drives.

The Data Protection for SAP DB2® keyword MAX_SESSIONS is used to define the number of parallel sessions to be established with the IBM Storage Protect server for database backup, archive (backup of log files) and restore. When you run a database backup, the data is typically written directly to tape drives on the IBM Storage Protect server. The parameter that is specified in the MAX_SESSIONS keyword must match the number of tape drives that are used simultaneously.

These must be available to the management class defined as BRBACKUPMGTCLASS in the Data Protection for SAP profile. When you set up the IBM Storage Protect server, make sure not to activate collocation in the (tape) storage pool that is defined for the management class that is chosen as BRBACKUPMGTCLASS. In addition, ensure that as many tape drives for this management class are available as the number of sessions that are defined in MAX_SESSIONS. Multiple access to the same tape might slow down data transfer.

These must be available to the management class defined as BRARCHIVEMGTCLASS in the Data Protection for SAP profile. If you are using tape pools as primary pools for this management class, this consideration for database backups also applies to disk storage pools. Several DB2 log archive sessions can simultaneously use one or two independent disk storage pools.

The number of storage pools that are required depends on the number of backup copies that are requested for a DB2 log file.

The Data Protection for SAP Oracle keywords MAX_SESSIONS, MAX_BACK_SESSIONS, MAX_ARCH_SESSIONS, MAX_RESTORE_SESSIONS, and are keywords used for defining the number of parallel sessions to be established with the IBM Storage Protect server for database backup, archive (backup of log files) and restore. When you run a database backup, the data is typically written directly to tape drives on the IBM Storage Protect server. The parameter that is specified in the MAX_SESSIONS keyword must match the number of tape drives that are used simultaneously.

These must be available to the management class defined as BRBACKUPMGTCLASS in the Data Protection for SAP profile. When you set up the IBM Storage Protect server, make sure not to activate collocation in the (tape) storage pool that is defined for the management class that is chosen as BRBACKUPMGTCLASS. In addition, ensure that as many tape drives for this management class are available as the number of sessions that are defined in MAX_SESSIONS. Multiple access to the same tape might slow down data transfer.

These must be available to the management class defined as BRARCHIVEMGTCLASS in the Data Protection for SAP profile. If you are using tape pools as primary pools for this management class, these considerations for database backups also apply to disk storage pools:
  • Several sessions of one BRARCHIVE operation can use one or two independent disk storage pools.
  • Several sessions of BRARCHIVE operations of different databases can simultaneously use one or two independent disk storage pools.

The number of storage pools that are required depends on the number of backup copies that are requested for a log file.