Error notification support for SIGDANGER signal
The AIX® Virtual Memory Manager (VMM) uses a combination of physical memory and disk storage to provide a virtualized memory space that is much larger than the actual physical memory.
The storage-based component of this system is called the paging space. If not enough paging space is configured or available, the systems performance can be diminished and certain system functions might begin to fail. In a high availability environment, you want to avoid this situation because it might lead to false failovers or failures during recovery of critical resources.
When paging space becomes too low, the AIX operating system generates a SIGDANGER signal for processes that are running on the system, including the PowerHA® SystemMirror® subsystems. When the PowerHA SystemMirror cluster manager or clstrmgr subsystem receives a SIGDANGER signal it creates an entry in the AIX system error log. You can create a notification method that is called whenever this situation occurs. You can use this notification method to configure an automatic response when the paging space becomes too low. The response from the notification method can be as simple as sending an alert to the system administrator, or as complex as automatically recovering the page space.
errnotify:
en_name = "ha_sigdanger"
en_persistenceflg = 1
en_resource = "clstrmgrDANGER"
en_method = "errpt -a -l $1 | mail -s 'SIGDANGER received' root"
en_method
field can specify a shell script or
other executable program. For this notification method to work, you
must specify the clstrmgrDANGER
setting in the en_resource
field.You can change the notification method entry by using the odmchange command. You can remove the notification method entry by using the odmdelete command.