VERITAS Storage Foundation 4.1 Cross-Platform Data Sharing Administrator's Guide

Glossary 57
disk group
A set of disks that are under VxVM control and share a common configuration. A disk group
configuration is a set of records containing detailed information on existing VERITAS Volume
Manager objects (such as disk and volume attributes) and their relationships. Each disk group has
an administrator-assigned name. Volumes can only be created on disks that belong to disk groups.
disk media name
A logical or administrative name chosen for a disk that is under the control of VxVM, such as
disk03. Also referred to a disk name.
DRL (Dirty Region Logging)
The method by which the VxVM monitors and logs modifications to a plex as a bitmap of changed
regions. For a volumes with a new-style DCO volume, the dirty region log is maintained in the
DCO volume. Otherwise, the dirty region log is allocated to an associated subdisk called a log
subdisk.
encapsulation
A process that converts existing partitions on a specified disk to volumes. If any partitions contain
file systems, /etc/fstab entries are modified so that the file systems are mounted on volumes
instead. This feature is only supported on the Linux and Solaris operating systems.
enclosure
A disk array.
gap
A disk region that does not contain VERITAS Volume Manager objects (subdisks).
HP-UX coexistence label
Data on disk which identifies the disk to the HP volume manager (LVM) as being controlled by
VxVM. The contents of this label are identical to the contents of the VxVM ID block.
mirror
A copy of a volume and its data. There can be several mirrors per volume. The terms mirror and
plex are used synonymously.
node
In the VxVM tree, a node is an element attached to the tree.
In a cluster environment, a node is a host machine in a cluster.