Required SAP Patches for Sun Cluster HA for SAP

The latest patch for the executable sapstart (see OSS note 0396321) protects you from multiple startups of SAP instances when an instance is already active on one node. The patch is important because duplication of SAP instances crashes the instance that was already active. Furthermore, the crash prevents SAP shutdown scripts from clean shut down of the SAP instances, which might cause data corruption.

To overcome this problem, install the latest patch for the sapstart executable, and configure the new parameter in the SAP startup profile for the application server and central instance.

For example, edit the profile SC3_DVEBMGS00 (the profile for the central instance) to add the new SAP parameter, sapstart/lockfile.

sapstart/lockfile =/usr/sap/SC3/DVEBMGS00/work/startup_lockfile

sapstart/lockfile

New parameter name.

/usr/sap/SC3/DVEBMGS00/work

Work directory for the central instance.

startup_lockfile

Lock file name that Sun Cluster HA for SAP uses.

You must locate the lock file path on the cluster file system. If you locate the lock file path locally on the nodes, start ups of the same instance from different nodes cannot be prevented.

Even if you configure the lock file in the SAP profile, you do not have to manually create the lock file. The Sun Cluster HA for SAP data service will create the lock file.

With this configuration, when you start the SAP instance, the SAP software locks the file startup_lockfile. If you start up the SAP instance outside of the Sun Cluster environment and then try to bring up SAP under the Sun Cluster environment, the Sun Cluster HA for SAP data service will attempt to start up the instance. However, because of the file-locking mechanism, this attempt will fail. The data service will log appropriate error messages in syslog.