VERITAS Volume Manager 4.1 Administrator's Guide

Chapter 6 211
6 Creating and Administering
Plexes
Introduction
This chapter describes how to create and maintain plexes. Plexes are
logical groupings of subdisks that create an area of disk space
independent of physical disk size or other restrictions. Replication
(mirroring) of disk data is set up by creating multiple data plexes for a
single volume. Each data plex in a mirrored volume contains an identical
copy of the volume data. Because each data plex must reside on different
disks from the other plexes, the replication provided by mirroring
prevents data loss in the event of a single-point disk-subsystem failure.
Multiple data plexes also provide increased data integrity and reliability.
NOTE Most VxVM commands require superuser or equivalent privileges.
Creating Plexes
NOTE Plexes are created automatically if you use the vxassist command or the
VERITAS Enterprise Administrator (VEA) to create volumes. For more
information, see “Creating a Volume” on page 228.
Use the vxmake command to create VxVM objects, such as plexes. When
creating a plex, identify the subdisks that are to be associated with it:
To create a plex from existing subdisks, use the following command:
# vxmake [-g diskgroup] plex plex sd=subdisk1[,subdisk2,...]
For example, to create a concatenated plex named vol01-02 using two
existing subdisks named disk02-01 and disk02-02, use the following
command:
# vxmake plex vol01-02 sd=disk02-01,disk02-02