Topics: AIX, System Admin


If FIRMWARE_EVENT entries appear in the AIX error log without FRU or location code callout, these events are likely attributed to an AIX memory page deconfiguration event, which is the result of a single memory cell being marked as unusable by the system firmware. The actual error is and will continue to be handled by ECC; however, notification of the unusable bit is also passed up to AIX. AIX in turn migrates the data and deallocates the memory page associated with this event from its memory map. This process is an AIX RAS feature which became available in AIX 5.3 and provides extra memory resilience and is no cause for alarm. Since the failure represents a single bit, a hardware action is NOT warranted.

To suppress logging, the following command will have to be entered and the partition will have to be rebooted to make the change effective:

# chdev -l sys0 -a log_pg_dealloc=false
Check the current status:
# lsattr -El sys0 -a log_pg_dealloc
More information about this function can be found in the "Highly Available POWER Servers for Business-Critical Applications" document which is available at the following link: (see pages 17-22 specifically).

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