VERITAS Volume Manager 3.5 Administrator's Guide (September 2002)

Creating a Mirrored Volume
170 VERITAS Volume Manager Administrator’s Guide
Creating a Mirrored Volume
A mirrored volume provides data redundancy by containing more than one copy of its
data. Each copy (or mirror) is stored on different disks from the original copy of the
volume and from other mirrors. Mirroring a volume ensures that its data is not lost if a
disk in one of its component mirrors fails.
Note A mirrored volume requires space to be available on at least as many disks in the
disk group as the number of mirrors in the volume.
To create a new mirrored volume, use the following command:
# vxassist [-b] [-g diskgroup] make volume length layout=mirror \
[nmirror=number] [init=active]
Note Specify the -b option if you want to make the volume immediately available for
use. See “Initializing and Starting a Volume” on page 181 for details.
For example, to create the mirrored volume, volmir, use the following command:
# vxassist -b make volmir 5g layout=mirror
To create a volume with 3 instead of the default of 2 mirrors, modify the command to
read:
# vxassist -b make volmir 5g layout=mirror nmirror=3
Creating a Mirrored-Concatenated Volume
A mirrored-concatenated volume mirrors several concatenated plexes. To create a
concatenated-mirror volume, use the following command:
# vxassist [-b] [-g diskgroup] make volume length \
layout=mirror-concat [nmirror=number]
Note Specify the -b option if you want to make the volume immediately available for
use. See “Initializing and Starting a Volume” on page 181 for details.
Alternatively, first create a concatenated volume, and then mirror it as described in
“Adding a Mirror to a Volume” on page 191.