HSM/utility phase

There are data sets that are not deleted and reallocated on a regular basis; however, they are not continuously allocated by an online application. Although these data sets are frequently in use, they do include a window of opportunity that will accommodate a migration. This window of opportunity will allow the use of either HSM or a standard utility to perform the migration.

When a new device type is replacing an old one, data sets must be moved from the old device to the new device. DFHSM provides the facility to perform such conversions of a volume using a single command. The command to convert a level 0 volume, will migrate all the data sets that are not in use on the source volume to migration level 1 - with the ability to recall them. This command makes it practical to clear a DASD migration volume so that it can be replaced with a different type of storage device.

Assume that you want to remove volume SG2002 from the system and replace it with a new volume. You must do three things:

1. Prevent new allocations to volume SG2002

   To prevent new allocations to the volume, you must change the status of the volume in the storage group. For example, you can establish the volume status in the storage group definition.

   STORAGE GROUP NAME: STGGP2 
   VOLUME SERIAL NUMBER: SG2002 
   SMS VOL  NAME 									STATUS 
   SG2002      ===> 	     DISNEW 

2. Remove the unallocated data sets that DFSMShsm can process from the volume using the following HSM Command:

   MIGRATE VOLUME(SG2002 MIGRATE(0)) CONVERT

   DFSMShsm migrates all of the unallocated data sets (NOT IN USE) that it can process off of volume SG2002 and recalls them to other SMS-managed volumes. The DFSMSdfp automatic class selection routine selects the volume for data set recall.

3. Remove the allocated data sets that DFSMShsm cannot process from the volume using zDMF.
   Note: DFDSS can also be used in this phase instead of HSM, but will require the creation of JCL.