Planning the Cluster Configuration Database Volume

As part of Sun Cluster installation and configuration, you configure a Cluster Configuration Database (CCD) volume to store internal configuration data. In a two-node cluster using VxVM, this volume can be shared between the nodes thereby increasing the availability of the CCD. In clusters with more than two nodes, a copy of the CCD is local to each node. See "Configuring the Shared CCD Volume" for details on configuring a shared CCD.

You cannot used a shared CCD in a two-node cluster using Solstice DiskSuite.

If each node keeps its own copy of the CCD, then updates to the CCD are disabled by default when one node is not part of the cluster. This prevents the database from getting out of synchronization when only a single node is up.

The CCD requires two disks as part of a disk group for a shared volume. These disks are dedicated for CCD use and cannot be used by any other application, file system, or database.

The CCD should be mirrored for maximum availability. The two disks comprising the CCD should be on separate controllers.

In clusters using VxVM, the scinstall(1M) script will ask you how you want to set up the CCD on a shared volume in your configuration.

Refer to Chapter 1, Understanding the Sun Cluster Environment, for a general overview of the CCD. Refer to the chapter on general cluster administration in the Sun Cluster 2.2 System Administration Guide for procedures used to administer the CCD.

Although the installation procedure does not prevent you from choosing disks on the same controller, this would introduce a possible single point of failure and is not recommended.