8464ch08_Migrate.fm Draft Document for Review February 7, 2020 3:15 pm Another way to ensure that two copies of the ML2 data exist is to use hierarchical storage  management (HSM) duplexing or the new Synchronous copy mode option support in the  TS7700. Both ways create two separate copies of the ML2 data before HSM deletes it.  Ideally, with a multi-cluster grid, you want one copy of the data in one cluster and the second  copy in another cluster to avoid loss of data if one of the clusters experiences a disaster. You  can use the Copy Consistency Points to ensure that each copy of the duplexed data is sent to  a separate cluster. The DFSMShsm RECYCLE function reduces the number of logical volumes inside the  TS7700, but when started, it can cause bottlenecks in the TS7700T recall process. If you  have a TS7700T with four physical drives, use a maximum of two concurrent DFSMShsm  RECYCLE tasks. If you have a TS7700T with six physical drives, use no more than five  concurrent DFSMShsm RECYCLE tasks. RECYCLE Select the RECYCLEPERCENT and consider the following points: GLYPH<SM590000> You free logical volumes on a stacked volume with hundreds of other logical volumes. GLYPH<SM590000> The space that is occupied by the logical volume is freed up only if and when the logical  volume is used (overwritten) again, unless you are using Expired Volume Management. GLYPH<SM590000> To RECYCLE, the TS7700 must load the input volumes into the TVC. GLYPH<SM590000> 5 for 1000 MiB, 2000 MiB, 4000 MiB, or 6000 MiB volumes GLYPH<SM590000> 10 for 400 MiB or 800 MiB volumes GLYPH<SM590000> RECYCLE SELECT (INCLUDE(RANGE(nnnnn:mmmmm))) GLYPH<SM590000> RECYCLE SELECT (EXCLUDE(RANGE(nnnnn:mmmmm))) Use a RECYCLEPERCENT value that depends on the logical volume size, for example: You can use the following commands to limit which volumes can be selected for DFSMShsm  RECYCLE processing. For example, you might want to limit RECYCLE to only your old  technology, and exclude the newer tape technology from RECYCLE until the conversion is  complete: You can also use the SETSYS RECYCLEOUTPUT to determine which tape unit to use for the  RECYCLE output tapes. You can use your ACS routines to route the RECYCLEOUTPUT unit  to the wanted library by using the &UNIT variable. For more information about implementing DFSMShsm, see  IBM z/OS DFSMShsm Primer ,  SG24-5272. No changes are required to any TMS to support basic TS7700. You review only the retention  and movement criteria for the data in the TS7700. You must check your daily tape  management process to delete any step that relates to EJECT activities. DFSMSrmm accepts logical volume capacity from an open close end-of volume (OCE)  module. DFSMSrmm can now always list the actual reported capacity from TS7700. 8.6 DFSMSrmm and other tape management systems Chapter 8. Migration  325