Example of a simultaneous-write operation during both migration and a client store operation

In this example, the storage pool hierarchy consists of a two primary storage pools. A single copy storage pool is defined to the pools. The simultaneous-write function during client store operations was enabled. However, one of the backed-up files was not written to the copy storage pool. The simultaneous-write function during migration is enabled.

Primary storage pools FILEPOOL and TAPEPOOL are linked to form a storage hierarchy. FILEPOOL is at the top of the storage hierarchy. TAPEPOOL is the next pool in the storage hierarchy. One copy storage pool, COPYPOOL, is defined to both FILEPOOL and TAPEPOOL:

• The simultaneous-write function during client store operations was enabled. (The setting of the AUTOCOPY parameter for FILEPOOL is CLIENT.)
• During client store operations, files A, B, and C were written to COPYPOOL. A failure occurred while writing file D to COPYPOOL
• The simultaneous-write function during migration is enabled for TAPEPOOL. (The setting of the AUTOCOPY parameter for TAPEPOOL is MIGRATION.)

The storage pool hierarchy and the copy storage pool that are associated with FILEPOOL and TAPEPOOL are displayed in Figure 1.

Figure 1. Storage pool hierarchy with files eligible to be migrated

See Figure 2.

Figure 2. A simultaneous-write operation during both migration and client backup operations

As a precaution, issue the BACKUP STGPOOL and COPY ACTIVEDATA commands after the migration operation has completed. Data that is simultaneously written to copy storage pools or active-data pools during migration is not copied when primary storage pools are backed up or when active data is copied.