Veritas Volume Manager 5.1 SP1 Administrator"s Guide (5900-1506, April 2011)

Creating a striped-mirror volume
A striped-mirror volume is an example of a layered volume which stripes several
underlying mirror volumes. A striped-mirror volume requires space to be available
on at least as many disks in the disk group as the number of columns multiplied
by the number of stripes in the volume.
To create a striped-mirror volume, use the following command:
# vxassist [-b] [-g diskgroup] make volume length \
layout=stripe-mirror [nmirror=number_of_mirrors] \
[ncol=number_of_columns] [stripewidth=size]
Specify the -b option if you want to make the volume immediately available for
use.
See “Initializing and starting a volume” on page 326.
By default, VxVM attempts to create the underlying volumes by mirroring subdisks
rather than columns if the size of each column is greater than the value for the
attribute stripe-mirror-col-split-trigger-pt that is defined in the vxassist
defaults file.
If there are multiple subdisks per column, you can choose to mirror each subdisk
individually instead of each column. To mirror at the subdisk level, specify the
layout as stripe-mirror-sd rather than stripe-mirror. To mirror at the column
level, specify the layout as stripe-mirror-col rather than stripe-mirror.
Mirroring across targets, controllers or enclosures
To create a volume whose mirrored data plexes lie on different controllers (also
known as disk duplexing) or in different enclosures, use the vxassist command
as described in this section.
In the following command, the attribute mirror=target specifies that volumes
should be mirrored between targets on different controllers.
# vxassist [-b] [-g diskgroup] make volume length \
layout=layout mirror=target [attributes]
Specify the -b option if you want to make the volume immediately available for
use.
See “Initializing and starting a volume” on page 326.
The attribute mirror=ctlr specifies that disks in one mirror should not be on the
same controller as disks in other mirrors within the same volume:
319Creating volumes
Mirroring across targets, controllers or enclosures