How the Monitor Script works

The monitor script nfs.mon, located in the directory/usr/local/cmcluster/nfstoolkit for Red Hat environments, and /opt/cmcluster/nfstoolkit for SLES environments), works by periodically checking the status of NFS services using the rpcinfo command. If any service fails to respond, the script exits, causing a switch to an adoptive node.

The monitor script monitors NFS services including:

If any of the services are dead or hung, the nfs.mon. will cause the package to fail.

	NOTE: To configure NFS for maximal availability, you must do the following: Specify AUTO_RUN=YES in the package configuration file. This allow the NFS package to start automatically when the cluster starts up, and to start on an adoptive node after a failure. Invoke the NFS Monitoring script, nfs.mon. The default NFS control script does not invoke the NFS monitoring script, nfs.mon. To invoke this script (see Chapter Chapter 3) trigger a failover if one of the package’s NFS services goes down while the node and network remain up.

Whenever the monitor script detects an event, it logs information to a file.The name of this file in legacy packages is same as your NFS control script in addition to a .log extension. For example, if your control script is called pkg01.cntl, the package log file is called pkg01.cntl.log. In Modular packages it uses the file specified in the script_log_file parameter of the package configuration file. Each NFS package has its own log file. The NFS monitor log file, which is on the same directory as the NFS control script, is always called hanfs.sh.log.