Veritas Storage Foundation Portable Data Containers: Cross-Platform Data Sharing 5.0.1 Administrators Guide, HP-UX 11i v3, First Edition, November 2009

DCO volume A special volume that is used to hold Persistent FastResync change maps, and
dirty region logs. The map layout within the DCO volume changed with the release
of VxVM 4.0, although the original format is still available. The old layout is
available in DCO Version 0 objects, and the new layout is available in DCO Version
20 objects.
device name The physical disk device name (or disk access name).
dirty region logging See DRL.
disk access name The device name or address that is used to access a physical disk on an operating
system, such as hdisk1 (AIX), c0t0d0 (HP-UX), disk11 (HP-UX 11i v3 onwards),
sda (Linux), or c0t0d0s2 (Solaris OS). In a SAN environment, it is more convenient
to use enclosurebased naming, which forms the device name by concatenating
the name of the enclosure (such as enc0) with the disk’s number within the
enclosure, separated by an underscore (for example, enc0_2).
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 as 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 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.
Glossary70