Creating FlashCopy image copies

You can configure certain utilities to create image copies by using the FlashCopy® function that is provided by z/OS® DFSMS and the IBM Storage Enterprise Storage Server (ESS) subsystems. FlashCopy can reduce both the unavailability of data during the copy operation and the amount of time that is required for recovery operations.

About this task

The following Db2 utilities support the creation of FlashCopy image copies:

  • COPY
  • LOAD
  • REBUILD INDEX
  • REORG INDEX
  • REORG TABLESPACE

FlashCopy image copies are output to VSAM data sets. The following utilities accept the VSAM data sets that are produced by FlashCopy as input:

  • COPYTOCOPY
  • DSN1COMP
  • DSN1COPY
  • DSN1PRNT
  • RECOVER

Procedure

To create a FlashCopy image copy:

Specify the FlashCopy option by using Db2 subsystem parameters, utility control statement parameters, or both.

You can use the FlashCopy subsystem parameters to define the FlashCopy option as the default behavior for each of the utilities that support the FlashCopy option. When the FlashCopy subsystem parameters are enabled as the default behavior, you do not need to specify the FlashCopy options in the utility control statement.

If you specify the FlashCopy options in both the subsystem parameters and the utility control statement parameters, the specifications in the utility control statement override the specifications of the subsystem parameters.

When creating a FlashCopy image copy, the COPY and LOAD utilities can include additional phases of execution, depending on the options that are specified in the utility control statement.

When creating a FlashCopy image copy, the following utilities also can create one to four additional sequential format image copies in a single execution:

  • COPY
  • LOAD with the REPLACE option specified
  • REORG TABLESPACE
Recommendation: To provide a recovery base for media failures, create one or more additional sequential format image copies when you create a FlashCopy image copy.