Guidelines for Working With Disk Sets

When working with disk sets, consider the following guidelines:

• Solaris Volume Manager must be configured on each host that will be connected to the disk set.

• Each host must have its local state database set up before you can create disk sets.

• To create and work with a disk set in a clustering environment, root must be a member of Group 14 on all hosts, or the /.rhosts file on each host must contain an entry for the other host names associated with the disk set.

• To perform maintenance on a disk set, a host must be the owner of the disk set or have reserved the disk set. A host takes implicit ownership of the disk set by putting the first disk into the disk set.

• You cannot add a disk to a disk set that is in use for a file system, database or any other application. Before you add a disk, make sure that it is not currently being used.

• Do not add to a disk set a disk containing existing data that you want to preserve. The process of adding the disk to the disk set repartitions the disk and destroys existing data.

• The default total number of disk sets permitted on a system is 4. You can increase this value up to 32 by editing the /kernel/drv/md.conf file, as described in How to Increase the Number of Default Disk Sets. The number of shared disk sets is always one less than the md_nsets value, because the local disk set is included in md_nsets.

• Unlike local volume administration, it is not necessary to manually create or delete state database replicas on the disk set. Solaris Volume Manager tries to balance a reasonable number of state database replicas across all disks in a disk set.

• When disks are added to a disk set, Solaris Volume Manager rebalances the state database replicas across the remaining disks. Later, if necessary, you can change the replica layout with the metadb command.