Veritas Volume Manager 4.1 Administrator's Guide (HP-UX 11i v3, February 2007)

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Creating and Administering Plexes

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 198.

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 from two existing subdisks

named mydg02-01 and mydg02-02 in the disk group, mydg, use the following

command:

# vxmake -g mydg plex vol01-02 sd=mydg02-01,mydg02-02