Considerations for using Advanced Image Copy Services

The following considerations and restrictions apply when using Advanced Image Copy Services.

Controlling the shadow data sets

If you specify ICEIN keywords in one of the following formats, IMS HP Image Copy creates shadow data sets internally:

  • FASTIC=(opt,FDUMP)
  • FASTIC=(opt,COPY), HDPC=Y, and VIC=Y or VIC=(Y,ONPC)

A shadow data set is a copy of the input database. The following considerations apply when creating shadow data sets:

  • To create a shadow data set in a non-SMS-managed environment, you must specify the SHDWVOLSER keyword to specify the volume on which the shadow data set is created.
  • Before you run an image copy job that creates shadow data sets, ensure that the system has enough DASD space to create shadow data sets. The shadow data sets require the same space as the space that is used by the input database. To create shadow data sets effectively, use the SHDW series keywords, which include SHDW_ERROR, SHDWDELETE, SHDWDSN, SHDWHLQ, SHDWMGMTCL, SHDWSTORCL, SHDWTCTL, and SHDWVOLSER.

HASH Check in creating Fast Recovery image copy

When creating a Fast Recovery image copy with FASTIC=(,COPY), you can enable the HASH Check option to verify the pointers. When the HASH Check option is enabled, the internal process flow of the Image Copy function is as follows:
  1. Creates a Fast Recovery image copy.
  2. Reads the data from the Fast Recovery image copy.
  3. Runs the HASH Check process for the data.
The elapsed time for the image copy job increases as compared to a job that runs without HASH Check.

Required access method definition of KSDS

In using concurrent copy by specifying the FASTIC=(,DUMP) keyword, the concurrent image copy processing (CIC or ACIC processing) for VSAM KSDS requires that the data set is SMS-managed and the BWO(TYPEIMS) parameter is specified on the AMS DEFINE or ALTER statement for the data set. This ensures that IMS HP Image Copy can detect CI or CA splits that cause the output image copy to be unusable. However, this does not apply when VIC=Y is specified and the HASH Check is disabled. For details, see VIC keyword.