3.5.3.7. /db2/backups/subsys1 & subsysX

Similar to /db2/backups/cfg, the /db2/backups/subsys1 filesystem temporarily stores backup images of the subsystem archived logs and database as they are generated. The backup files are then transferred to long-term media, such as tape, using a backup file manager such as TSM. Details are described in the Section 3.5.4.4: DB2 Disk Space on page 77. Separate filesystems are allocated for each subsystem defined in the system.

Ensure that it has sufficient space to store the data generated by each backup; otherwise the backup will fail. If the required backup space exceeds the maximum size for a JFS filesystem (about 63.8 GB), consider using a JFS2 filesystem. Other options include having

DB2 compress the backup data as it is taken or having DB2 store the backup data onto more than one filesystems.

3.5.3.8. /db2/log/cfg

Though small in comparison to the DB2 subsystem logging area, the /db2/log/cfg filesystem is recommended to store the 'CFG' transaction logs in a separate filesystem from the configuration and 'CFG' tables.

3.5.3.9. /db2/log/subsys1 & subsysX

The subsys1 and subsequent subsystem databases require a separate filesystem to store the DB2 transaction logs. The /db2/log/subsys1 filesystem size is discussed in Section 3.5.4.4: DB2 Disk Space on page 77.

3.5.3.10. /db2/mirror-log/cfg

This filesystem is similar to that of /db2/log/cfg, but the storage resources for the DB2 log must be separate from the resource of the primary copy. DB2 is configured so that it writes to both the primary and secondary log copies as transactions are registered by the database.

3.5.3.11. /db2/mirror-log/subsys1 & subsysX

This filesystem is similar to that of /db2/log/subsys1, but the storage resources for the DB2 log must be separate from the resource of the primary copy. DB2 is configured so that it writes to both the primary and secondary log copies as transactions are registered by the database.

3.5.3.12. /db2/mirror-backup/cfg

This filesystem is smaller than /db2/backups/cfg since it will only contain archived copies of the mirrored copy of the 'CFG' logs. Similar to /db2/backups/cfg, it needs to be managed by a backup tool such as TSM.

3.5.3.13. /db2/mirror-backup/subsys1 & subsysX

This filesystem is smaller than /db2/backups/subsys1 since it will only contain archived copies of the mirrored copy of the 'SUBSYS1' logs. Similar to /db2/backups/subsys1, it needs to be managed by a backup tool such as TSM.

3.5.3.14. SUBSYS1 Database Allocation

The recommended allocation of disk space for the SUBSYS1 (and other subsystems) database is shown in Figure 5: on page . By default, mkhpss will distribute the database tables and indexes across the 9 logical volumes/partitions shown in the diagram. Specifics of mkhpss are described in

HPSS Installation Guide

July 2008

Release 6.2 (Revision 2.0)

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IBM HPSS manual 3.7. /db2/backups/subsys1 & subsysX, 3.8. /db2/log/cfg, 3.9. /db2/log/subsys1 & subsysX