IV20782: ADD ALUA TO APPCM APPLIES TO AIX 7100-02

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Support needed for ALUA devices in the APPCM.
  

Local fix

Problem summary

• Support needed for ALUA devices in the APPCM.
  

Problem conclusion

• a. Detect the ALUA functionality of the storage and ascertain
     whether or not the storage is in ALUA mode.
  
  b. The APPCM must be able to run in either active-passive or
     ALUA mode.
  
  c. Handle the ALUA specific, vendor specific, and generic check
     conditions.
  
  d. The existing active-passive PCM must (when in ALUA mode)
     allow for the selection of non-optimized paths if there are
     no optimized paths available.
  
  e. In ALUA mode the APPCM will, after a check condition, use
     Inquiry C9 to determine if a check condition is due to an
     error or CCDL.  If it is not due to CCDL then standard error
     processing (delay and retry or select a new path) will
     apply.  If due to a CCDL or a controller reset the APPCM may
     inject additional delays or retries and do a poll of the
     controllers before resuming normal I/O.
  
  f. The ALUA APPCM will use the Inquiry C9 SCSI command to
  deter-
     mine the state of a path.
  
  g. The ALUA APPCM will detect paths that have failed due to
     error injection and route the I/O to the paths that have not
     failed. The path selection will be based on the available
     path information obtained from the Inquiry C9 command. Opti-
     mized paths will have precedence over non-optimized ones.
  
  h. The APPCM will support all ALUA states (Optimized, Non-Opti-
     mized, Unavailable and Standby) with Standby and Unavailable
     treated in the same manner.
  
  i. The APPCM will handle an existing configured (either opened
     or closed) disk changing from ALUA to non-ALUA (and vice
     versa). The APPCM will need to query (via Inquiry C9) if
     ALUA is supported when unit attentions are reported that the
     device mode (ALUA, non-ALUA) has possibly changed.
  
  j. The ALUA APPCM health check will utilize Inquiry C9.
  
  k. mpio_get_config will have a flag added that will display the
     state of the paths and whether or not ALUA mode is enabled.
     This flag will also display the optimized controller for
     each lun.
  
  l. Existing boot/ras/dump will remain the same.
  

Temporary fix

Comments

• 6100-08 - use AIX APAR IV20733
  7100-02 - use AIX APAR IV20782
  

APAR Information

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

  IV20733

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

Fix information

• Fixed component name

  AIX V7.1

• Fixed component ID

  5765H4000

Applicable component levels

• R710 PSY U846327

     UP12/11/02 I 1000

PTF to Fileset Mapping

• U846327 devices.common.IBM.mpio.rte 7.1.2.0