OA48844: IPL ALTERNATE SUBCHANNEL SET, DUPLICATE VOLUMES UNDETECTED 15/09/21 PTF PECHANGE

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• After applying PTFs UA90740 (HBB7780) or UA90741
  (HBB7790) for APAR OA44240, duplicate volumes may come online
  when IPLing from the alternate subchannel set.
  
  For example, devices B000/1B000 are a PPRC pair.  Device A000
  has the same VOLSER as B000/1B000. When IPLing SS1, both devices
  A000 and 1B000 come online with the same volser. Device B000
  remains offline as expected.
  
  Known Environment:
  Systems running with alternate Subchannel Sets at IPL with the
  PTFs for APAR OA44240 installed and active.
  .
  Known Impact:
  Potential data integrity issue due to undetected ONLINE
  duplicate VOLIDs when IPLing with an alternate subchannel set
  with a configuration error (and no error message).
  .
  PE Information:
  User's Affected: Users at HBB7780 and above with the PTFs for
  APAR OA44240 (UA90740 at HBB7780 or UA90741 at HBB7790)
  installed and active.
  .
  User Impact:
  OA44240 PTFs:
  HBB7780 PSY UA90740
  HBB7790 PSY UA90741
  .
  APAR OA44240 provides a large amount of new function and
  capability but introduces this problem when using multiple
  subchannel sets and mismatched configurations.
  .
  Recommendation:
  Keep the PTFs on to enable all the new functions but use extra
  care when IPLing a recently updated configuration and IPLing the
  system with an alternate subchannel set.
  

Local fix

• Manually vary offline one of the duplicate volumes.  Subsequent
  VARY will not allow for the duplicate volumes to be brought
  online simultaneously
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: Users at HBB7780 and above with the PTFs for *
  *                 OA44240 (UA90740 and UA90741) installed      *
  *                 and running with an alternate subchannel set *
  ****************************************************************
  * PROBLEM DESCRIPTION: During IPL with an alternate            *
  *                      subchannel set, IPL phase duplicate     *
  *                      VOL ID check processing is NOT          *
  *                      detecting duplicate volume IDs thus     *
  *                      allowing multiple volumes with the      *
  *                      same ID to be online at the same time.  *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  During IPL with an alternate subchannel set duplicate
  VOL ID Check processing is scanning the list of online
  devices for the CURRENT subchannel set instead of the
  ACTIVE one.
  

Problem conclusion

• Change the DUP VOL ID check processing in IEAVNP02 to use the
  ACTIVE subchannel set when scanning onine devices for duplicates
  

Temporary fix

• *********
  * HIPER *
  *********
  

Comments

APAR Information

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

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

  UA79791 UA79792 UA79793

Modules/Macros

• IEAVNP02
  

Fix information

• Fixed component name

  IOS

• Fixed component ID

  5752SC1C3

Applicable component levels

• R7A0 PSY UA79791

     UP15/12/23 P F512 ®

• R780 PSY UA79792

     UP15/12/23 P F512 ®

• R790 PSY UA79793

     UP15/12/23 P F512 ®

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.