PRIMECLUSTER Installation and Administration Guide 4.2 (Linux for Itanium)

9.3.1 Notes on Applying Corrections to the PRIMECLUSTER System

Note the following when you apply intensive correction to the cluster system.

• Back up the system environment before you attempt to apply a correction.

• The software version to be installed on each node must be the same on all nodes in the cluster system. Also, the corrections must be the same on all the nodes constituting the system. Note, however, that this is not always true when rolling update, described below, is allowed.

• To apply an intensive correction, you must stop the node temporarily. This means that the job must be stopped, albeit temporarily. You should consider a maintenance plan to ensure that the maintenance is completed within a specified period. You must also examine the time and duration of the maintenance to minimize the impact on a job.

• Rolling update is a method by which software is updated while the job continues to operate by executing job failover for a node in a cluster to separate the standby node from the operation in order to apply corrections to the node one by one.
  If you apply this method, the job stop time required for software update can be minimized. To perform update with this method, however, you must satisfy the prerequisites for rolling update (the items to be corrected must be correctible with rolling update).
  To apply this method, you must confirm the contents of the README file for the relevant patch and then contact your Fujitsu systems engineer (SE).