Recovery of FlashCopy image copies

Using FlashCopy® image copies can reduce the amount of time that is required for recovery operations.

To provide a recovery base for media failures, create one or more additional sequential format image copies when you create a FlashCopy image copy. If the FlashCopy image copy has been migrated or deleted, the recovery proceeds from the sequential image copies if available. The following utilities can create additional sequential format image copies in a single execution:

• COPY
• LOAD with the REPLACE option specified
• REORG TABLESPACE

You can recover an object to a specific FlashCopy image copy by specifying the RECOVER utility with the TOCOPY, TOLASTCOPY, or TOLASTFULLCOPY options. If the object is partitioned, you must specify the data set number on the DSNUM parameter in the RECOVERY utility control statement for each partition that is being recovered.

A FlashCopy image copy with consistency consumes more processing resources when the image copy is created, and when the image copy is used for recovery. To recover from a FlashCopy image copy with consistency, the RECOVER utility must read the logs to apply changes that were made to the recovered object after the point of consistency. Some of the changes could be work that was previously backed out and that must be reapplied, because the work was uncommitted when the FlashCopy image copy was created.

For recovery to a log point or full recovery, if uncommitted work was backed out from the FlashCopy image copy during consistency processing, recovery requires more analysis of the logs during the preliminary LOGCSR phase (PRELOGC). The preliminary log apply phase (PRELOGA) and the other log phases also require more analysis.