PQ60846: TSM RECLAMATION PROCESS APPEARS TO HANG THE SERVER.

APAR status

• Closed as program error.

Error description

• Reclamation processing for TSM in systems where there are
  a large number of storage pools and/or a large number of
  volumes may appear to HANG the server.  The server is
  not actually hung in this case, it will just appear to
  STALL.  The problem is that reclamation starts a number of
  processes very quickly which can monopolize server locks
  while doing the volume selection.  While this volume selection
  is being done, it can cause other server actions requiring
  finished their selections.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: TSM Server users for ANY server platform     *
  *                 where there are either a large number        *
  *                 of storage pools (greater than 10) or        *
  *                 a large number of volumes (greater than      *
  *                 100) or both.                                *
  ****************************************************************
  * PROBLEM DESCRIPTION: When the server begins reclamation      *
  *                      processing, it starts a process         *
  *                      for each storage pool.  Each process    *
  *                      then acquires a number of server        *
  *                      locks and evaluates volumes for         *
  *                      candidates to be reclaimed.  During     *
  *                      this selection processing, if there     *
  *                      are a large number of storage pools     *
  *                      and/or a large number of volumes,       *
  *                      these reclamation processes can         *
  *                      monopolize server locks and cause       *
  *                      other activities on the server to       *
  *                      wait until the reclamation volume       *
  *                      selection completes.                    *
  ****************************************************************
  * RECOMMENDATION: Apply the ptf containing this fix once it    *
  *                 is available.                                *
  ****************************************************************
  The TSM reclamation processing on the server can result
  in multiple reclamation processes holding locks that
  other server actions/processes may need.  This can result
  in other processes having to wait until the volume selection
  for reclamation completes.
  

Problem conclusion

• The TSM reclamation volume selection processing has
  been modified to allow other server activities
  to get access to the needed server locks.  The
  reclamation volume selection processing has been
  modified to prevent all the reclamation processes from
  monopolizing the server locks at the same time.
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

  IC32972

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  TSM FOR OS/390

• Fixed component ID

  5698ISMVS

Applicable component levels

• R511 PSY

     UP