A VM disk typically includes a public region (allocated storage) and a private region where Volume Manager internal configuration information is stored.

A disk group is a collection of VM disks that share a common configuration.

A disk group configuration is a set of records with detailed information about related Volume Manager objects, their attributes, and their connections.

Volumes are created within a disk group. A given volume must be configured from disks in the same disk group.

A subdisk is a set of contiguous disk blocks. A block is a unit of space on the disk. Volume Manager allocates disk space using subdisks.

The Volume Manager uses subdisks to build virtual objects called plexes. A plex consists of one or more subdisks located on one or more physical disks.

A volume is a virtual disk device that appears to applications, databases, and file systems as a physical disk, but does not have the physical limitations of a physical disk device.

A volume consists of one or more plexes, each holding a copy of the selected data in the volume. Due to its virtual nature, a volume is not restricted to a particular disk or a specific area of disk.

A volume can consist of up to 32 plexes, each of which consists of one or more subdisks.