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Simplified Data Migration with z/OS V2R2

  

z/OS V2R2 DFSMShsm provides a MOVE option to perform data migration from small to large disk volumes with three simple steps:
 

  1. Define large volumes and vary them online.image
  2. Set the SMS status of the small volumes to DISNEW or DISALL. 
    (This prevents SMS from selecting these volumes for new allocations).
  3. Issue the MIGRATE VOLUME command with the new MOVE option: 
    MIGRATE VOLUME(SML001, SML002, SML003) MOVE

During MOVE processing, DFSMShsm selects each eligible data set on each volume and invokes DFSMSdss COPY with DELETE using standard SMS ACS allocation to perform the move.  Since the newly defined large volumes have the most free space, they will be automatically selected as the target location of the moves.


This function provides a considerable advantage when processing open DB2 and CICS data sets and mounted zFS file systems in that it temporarily closes/unmounts them in order to make them eligible for processing.  When combined with the Preserve Mirror function, all open DB2 and CICS data sets and mounted zFS files on a volume can be moved to another volume in a matter a minutes.  

For example, to move all open DB2 data sets from a small volume to a large volume, perform the following:

  1. Define a large volume and vary it online.
  2. Update the management class to which the DB2 data sets are defined.
    1. Set SERIALIZATION ERROR EXIT to 'DB2'
      This indicates that if a DB2 data set is open when DFSMShsm attempts to move it, that DFSMShsm should first invoke DB2 to close the data set.  After the movement is complete, DFSMShsm reopens the data set via DB2.
    2. Set TRANSITION COPY TECHNIQUE to 'PRESERVEMIRRORREQUIRED'.
      Preserve Mirror enables FlashCopy to be used to move the data simultaneously at both the local and remote sites in a metro mirror environment.
  3. Set the SMS status of the small volume to DISNEW or DISALL.
  4. Issue the MIGRATE VOLUME command with the new MOVE option:  MIGRATE VOLUME(SML001) MOVE

As DFSMShsm processes each DB2 data set, it will invoke DB2 to close the data set, invoke DFSMSdss to move the data set with FlashCopy at both the local and remote site, and then reinvoke DB2 to reopen the data set.  (The data set will be skipped if it has active DB2 transactions).  This process enables active DB2 databases to be moved to larger disk volumes with minimal application impact.  

The MOVE option can also be specified at the data set and storage group level.