IZ91236: UNMAPPED DS3/4/5K LUN MAY BLOCK I/O TO OTHER LUNS IN ARRAY. APPLIES TO AIX 5300-10

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• A LUN on a DS3K, DS4K, or DS5K SAN is unmapped when running
  default AIX MPIO PCM.  All the I/O for that LUN fails as
  expected.  However; if the LUN is kept open, then it may
  attempt a failover causing I/O to other LUNs under the
  same Array to blocked while the failover is retrying.  The
  failover will not succeed due to the LUN being unmapped,
  but I/O to other LUNs may be blocked for minutes.
  

Local fix

Problem summary

• A LUN on a DS3K, DS4K, or DS5K SAN is unmapped when running
  default AIX MPIO PCM.  All the I/O for that LUN fails as
  expected.  However; if the LUN is kept open, then it may
  attempt a failover causing I/O to other LUNs under the
  same Array to blocked while the failover is retrying.  The
  failover will not succeed due to the LUN being unmapped,
  but I/O to other LUNs may be blocked for minutes.
  

Problem conclusion

• Do not allow failover to be attempted to LUN that has been
  unmapped (on the Storage).
  

Temporary fix

Comments

• 5300-10 - use AIX APAR IZ91236
  5300-11 - use AIX APAR IZ90799
  5300-12 - use AIX APAR IZ90848
  6100-03 - use AIX APAR IZ87745
  6100-04 - use AIX APAR IZ87767
  6100-05 - use AIX APAR IZ87652
  6100-06 - use AIX APAR IZ86778
  7100-00 - use AIX APAR IZ86518
  

APAR Information

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

  IZ86419

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

Fix information

• Fixed component name

  AIX 5.3

• Fixed component ID

  5765G0300

Applicable component levels

• R530 PSY U840558

     UP11/02/23 I 1000

PTF to Fileset Mapping

• U840558 devices.common.IBM.mpio.rte 5.3.10.4