Reconstructing the source and target units after the test

Before remote copy modee is resumed, the remote copy pair must be checked for data differences, and a decision must be made as to whether to accept the differences on the source or on the target unit.

Actions on the standby system

Access of the standby system to the target units must be interrupted; processing is resumed over the source path.

/SET-REMOTE-COPY-ACCESS
  UNIT=<MN der Target-Unit> / *BY-PUBSET(PUBSET=<cat-id>) /
       *BY-VOLUME(VOLUME=<vsn>) >) / 
       *BY-SYMMETRIX(SERIAL-NUMBER=<target serialnumber>
  ,LOGICAL-VOLUME=*ALL-TARGET-UNITS(RA-GROUP=<no>))
  ,TARGET-ACCESS=*BY-SOURCE

Actions on the local system

Check whether there is a data difference between the source unit and target unit (not for VMAX3).

/SHOW-SYMMETRIX-DEVICE-CONFIG
  UNIT=<MN of source unit> / <MN of target unit>
  ,CONFIGURATION=*REMOTE-COPY-PAIRS
  ,INFORMATION=*PHYSICAL

Depending on the result of the SHOW output, a decision must be made on the appropriate action.

• Keep the changes on the source units (i.e. all changes made on the target unit during the recovery tests are discarded).

  /RESUME-REMOTE-COPY
    UNIT=<MN of source unit> / *BY-VOLUME(VOLUME=<vsn>) /
         *BY-PUBSET(PUBSET=<cat-id>) / *BY-SYMMETRIX(SERIAL-NUMBER=<ser-no>
    ,LOGICAL-VOLUME=*ALL-SOURCE-UNITS(RA-GROUP=<no>))
    ,RESTORE=*FROM-SOURCE
    ,WAIT=*UNTIL-SYNCHRONIZATION
  

• Keep the changes on the target units (i.e. all changes made on the source unit during the recovery tests are discarded).

  • Terminate the applications on the source units (but the source unit should remain attached).

  • Start the restore process.

    /RESUME-REMOTE-COPY
      UNIT=<MN of source unit> / *BY-VOLUME(VOLUME=<vsn>) /
           *BY-PUBSET(PUBSET=<cat-id>) / 
           *BY-SYMMETRIX(SERIAL-NUMBER=<ser-no>
      ,LOGICAL-VOLUME=*ALL-SOURCE-UNITS(RA-GROUP=<no>))
      ,RESTORE=*TO-SOURCE
      ,WAIT=*UNTIL-SYNCHRONIZATION
    

The WAIT operand specifies whether the command is to wait until synchronization is terminated or, in asynchronous processing mode (SRDF/A), for consistency (WAIT=*UNTIL-SYNCHRONIZATION) or not (WAIT=*NO). This simplifies the programming of test procedures for recovery because extensive queries regarding the synchronization progress of the remote copy pair are unnecessary.