DFSMSdss can use FlashCopy® to quickly move data from a source location to a target location when the following requirements exist:

• The source and target device types must be the same.
• The source devices and the target devices must be in the same ESS.
• The ESS must support data set FlashCopy (data set FlashCopy).
• The FASTREPLICATION(NONE) keyword is not specified.
• The data must not need manipulation. The following types of processing require data manipulation:
  • Reblocking — Reblocking occurs when you specify the REBLOCK keyword or when the VTOC indicates that the data set can be reblocked.
  • PDS compression — DFSMSdss compresses a PDS data set during copy processing, by default. You can specify the NOPACKING keyword to prevent DFSMSdss from compressing the PDS, thereby allowing the use of FlashCopy.
  • Changing stripe counts — The source stripe count must be the same as the target stripe count for a striped extended format data set.
  • An individual stripe extending to more than one volume — A single-striped sequential-extended format data set cannot use FlashCopy if either the source data set or the target data set is multivolume.
  • PDS or PDSE conversion — Conversion occurs when you specify the CONVERT keyword with these data sets.
  • Block-by-block processing of direct access data sets — Block-by-block processing occurs when you specify the RELBLOCKADDRESS or the AUTORELOCKADDRESS keyword.
  • Utilities — FlashCopy cannot be used if your data must be moved with the use of a utility.

DFSMSdss attempts to allocate the target data set on the same device type in the same ESS if the source data is in an ESS. This increases the probability that FlashCopy can be used to copy the data. However, FlashCopy cannot be used if the source data set is multivolume and is not contained entirely in one ESS subsystem. The reason that FlashCopy cannot be used is because all source and target devices must be in one ESS subsystem in order to establish a FlashCopy relationship. These data sets will not be processed with FlashCopy and will be allocated to whatever volumes are available, irrespective of their FlashCopy capability.

DFSMSdss FlashCopy Batch Protection allows DFSMSdss to direct a fast replication request to the storage group ACS routine. The ACS routine then assigns a storage group to allocate the data set during a logical data set COPY to SMS operation. This enables users, without modifying existing batch jobs, to have a set of volumes dedicated for FlashCopy usage, limiting situations in which a volume is selected that does not allow FlashCopy to be used (such as when a volume is a Global Mirror volume or a z/OS Global Mirror (XRC) primary).

IF &ACSENVR2 = 'FLASHCPY' THEN SET &STORGRP = 'fcstrgrp'

For more information, refer to ACS routine information.