Disabling LLT, GAB, and I/O fencing on a single node cluster


Disabling LLT, GAB, and I/O fencing on a single node cluster
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This section discusses how to disable kernel modules on a single node VCS cluster.

Typically, LLT, GAB, and I/O fencing kernel modules are loaded on a node when you install VCS. However, you can disable LLT, GAB, and I/O fencing modules if you do not require high availability for the applications. You can continue to manage applications on the single node and use the application restart capabilities of VCS.

If you later decide to extend the cluster to multiple nodes, you can enable these modules and make the applications highly available across multiple nodes.

Note:

If VCS engine hangs on the single node cluster with GAB disabled, GAB cannot detect the hang state and cannot take action to restart VCS. For such a condition, you need to detect that VCS engine has hung and take corrective action. For more information, refer to the 'About GAB client process failure' section in the Cluster Server Administrator's Guide.