For example, a file system cannot be unmounted, because of a process running on it. Then, you might want to kill that process first, before unmounting the file system, in order to get the event script done. Now, since the event script didn’t succeed in its first run, the Retry feature enables HACMP for AIX to retry it until it finally succeeds, or the retry count is reached.
5.1.5 Notes on Customizing Event Processing
You must declare a shell (for example #!/bin/sh) at the beginning of each script executed by the notify, recovery, and pre- or
Notify, recovery, and pre- and
Synchronizing the cluster configuration does not propagate the actual new or changed scripts; you must add these to each node manually. Also, it is allowed to have different contents in these scripts on different nodes in order to be able to act upon different environments. However, the name of these scripts, their location in the file system, and their permission bits have to be identical.
5.1.6 Event Emulator
To test the effect of running an event on your cluster, HACMP for AIX provides a utility to run an emulation of an event. This emulation lets you predict a cluster's reaction to an event as though the event actually occurred. The emulation runs on all active nodes in your cluster, and the output is stored in an output file. You can select the path and name of this output file using the EMU_OUTPUT environment variable, or, use the default /tmp/emuhacmp.out file on the node that invoked the Event Emulator.
For more information on event emulation, see these chapters: “Administrative
Facilities” in the HACMP for AIX, Version 4.3: Concepts and Facilities,
5.2 Error Notification
The AIX Error Notification facility detects errors matching predefined selection criteria and responds in a programmed way. The facility provides a wide range of criteria that you can use to define an error condition. These errors are called notification objects.
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