2.2.8.2 File Systems With VERITAS VxFS

You can create UNIX File System (UFS) or Veritas File System (VxFS) file systems in the disk groups of logical hosts. When a logical host is mastered on a cluster node, the file systems associated with the disk groups of the logical host are mounted on the specified mount points of the mastering node.

When you reconfigure logical hosts, Sun Cluster must check the file systems before mounting them, by running the fsck command. Even though the fsck command checks the UFS file systems in non-interactive parallel mode on UFS file systems, this still consumes some time, and this affects the reconfiguration process. VxFS drastically cuts down on the file system check time, especially if the configuration contains large file systems (greater than 500 Mbytes) used for data services.

When setting up mirrored volumes, always add a Dirty Region Log (DRL) to decrease volume recovery time in the event of a system crash. When mirrored volumes are used in clusters, DRL must be assigned for volumes greater than 500 Mbytes.

With SSVM and CVM, it is important to estimate the maximum number of volumes that will be used by any given disk group at the time the disk group is created. If the number is less than 1000, default minor numbering can be used. Otherwise, you must carefully plan the way in which minor numbers are assigned to disk group volumes. It is important that no two disk groups shared by the same nodes have overlapping minor number assignments.

As long as default numbering can be used and all disk groups are currently imported, it is not necessary to use the minor option to the vxdg init command at disk group creation time. Otherwise, the minor option must be used to prevent overlapping the volume minor number assignments. It is possible to modify the minor numbering later, but doing so might require you to reboot and import the disk group again. Refer to the vxdg(1M) man page for details.