A.2.7.5 Using VxFS File Systems

You can configure and specify either UFS or VxFS file systems associated with a logical host's disk groups on volumes of type fsgen. When a cluster node masters a logical host, the logical host's file systems associated with the disk groups are mounted on the mastering node's specified mount points.

During a logical host reconfiguration sequence, it is necessary to check file systems with the fsck(1M) command. Though this process is performed in non-interactive parallel mode on UFS file systems, it can affect the overall time of the reconfiguration sequence. The logging feature of UFS, SDS, and VxFS file systems greatly reduce the time that fsck(1M) takes prior to mounting file systems.

When the switchover of a data service is required along with volume recovery, the recovery takes longer than allowed in the reconfiguration steps. This causes step time-outs and the node aborts.

Consequently, when setting up mirrored volumes, always add a DRL log to decrease volume recovery time in the event of a system crash. When mirrored volumes are used in the cluster environment, DRL must be assigned for volumes greater than 500 Mbytes.

Use VxFS if large file systems (greater than 500 Mbytes) are used for HA data services. Under most circumstances, VxFS is not bundled with Sun Cluster and must be purchased separately from Veritas.

Although it is possible to configure logical hosts with very small mirrored file systems, you should use Dirty Region Logging (DRL) or VxFS file systems because of the possibility of time-outs as the size of the file system increases.