7.1 Patching Sun Cluster Overview

Due to the nature of a cluster, all cluster member nodes must be at the same patch level for proper cluster operation. When patching a node with a Sun Cluster-specific patch, you might need to temporarily remove a node from cluster membership or stop the entire cluster before installing the patch. This section describes these steps.

Before applying a Sun Cluster patch, first check the Sun Cluster web page for any special instructions; for the current URL, see the Sun Cluster 3.0 Release Notes or contact Enterprise Services. If there aren't any special instructions, check the patch's README file.

For Sun Cluster-specific patches, always defer to the patch's README file for instructions that supersede procedures in this chapter.

Patch installation on all cluster nodes falls into one of the following scenarios:

• Rebooting patch (node)--A node must be booted to single-user mode before the patch can be applied, then rebooted to join the cluster. In doing so, you need to put the node into a "quiet" state by first switching any resource groups or disk device groups from the node to be patched to another cluster member. Also, you apply the patch to one cluster node at a time to avoid bringing down the entire cluster.

  The cluster itself remains available during this type of patch application, even though individual nodes are temporarily shut down. A patched node is able to rejoin a cluster as a member node even though other nodes are not yet at the same patch level.

• Rebooting patch (cluster and firmware)--The cluster must be shut down and each node must be booted to single-user mode to apply the software or firmware patch. Then you reboot the nodes to rejoin the cluster. For this type of patch, the cluster is unavailable during patch application.

• Non-rebooting patch--A node does not have to be in a "quiet" state (it can still be mastering resource groups or device groups), nor does it have to be shut down or rebooted when applying the patch. However, you should still apply the patch to one node at a time and verify that the patch works before patching another node.

Underlying cluster protocols do not change due to a patch.

You use the patchadd command to apply a patch to the cluster, and patchrm to remove a patch (when possible).

7.1.1 Sun Cluster Patch Tips

Use the following tips to help you administer Sun Cluster patches more efficiently:

• Refer to the Sun Cluster website for any special instructions associated with the patch or firmware update. For the current URL, see the Sun Cluster 3.0 Release Notes or contact Enterprise Services.

• Always read the patch README file before applying the patch.

• Apply all patches (required and recommended) before running the cluster in a production environment.

• Check the hardware firmware levels and install any required firmware updates that may be needed.

• All nodes acting as cluster members must have the same patches.

• Keep cluster subsystem patches up to date. This includes volume management, storage device firmware, cluster transport, and so forth.

• Review patch reports regularly, such as once a quarter, and patch a Sun Cluster configuration using the recommended patch suite.

• Apply selective patches as recommended by Enterprise Services.

• Test failover after major patch updates; be prepared to back out the patch if cluster operation is degraded or impaired.