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

56 VERITAS Storage Foundation CDS Administrator’s Guide
cluster
A set of host machines (nodes) that shares a set of disks.
cluster file system
See CFS.
current-rev disk group
A disk group created using a version of VxVM providing CDS functionality; however, the CDS
attribute is not set. If the CDS attribute is set for the disk group, the disk group is called a CDS disk
group.
data change object
See DCO.
DCO (Data Change Object)
A VxVM object that is used to manage information about the FastResync maps in the DCO
volume. Both a DCO object and a DCO volume must be associated with a volume to implement
Persistent FastResync on that volume.
DCO volume
A special volume that is used to hold Persistent FastResync change maps, and dirty region logs (see
dirty region logging). 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), sda (Linux), or c0t0d0s2 (Solaris OS). In a SAN
environment, it is more convenient to use enclosure-based 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).