About cluster disk groups and volumes


About cluster disk groups and volumes
Prev	Creating disk groups and volumes	Next

SFW uses disk groups to organize disks or LUNs for management purposes. A dynamic disk group is a collection of disks that is imported or deported as a single unit. A cluster disk group is a special type of dynamic disk group that is created on shared storage and is designed to be moved or to failover between hosts. In order to prevent data corruption a cluster disk group uses SCSI reservations to protect the shared disks and limits access to a single host at a time.

Volumes are logical entities that are comprised of portions of one or more physical disks and are accessed by a drive letter or mount point. Volumes can be configured for performance and high availability.

Note:

You create a cluster disk group and volumes on only one node of a cluster. The volumes can be accessed by other nodes in a high-availability cluster by first deporting the cluster disk group from the current node and then importing it on the desired node. In a campus cluster, the volumes are mirrored across the storage arrays.

Note:

If your storage devices are SCSI-3 compliant, and you wish to use SCSI-3 Persistent Group Reservations (PGR), you must enable SCSI-3 support using the Veritas Enterprise Administrator (VEA - Control Panel - System Settings). For more information, see the Storage Foundation Administrator's Guide.

Before you create a disk group, consider the following items:

The type of volume configurations that are required
The number of LUNs required for the disk group
The implications of backup and restore operations on the disk group setup
The size of databases and logs that depend on the traffic load
The disk groups and number of disks on each site
Types of volumes required and location of the plex of each volume in the storage array