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

Chapter 7, Creating Volumes
Creating a Volume with a Version 0 DCO Volume
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2. Use the following command to create the volume (you may need to specify additional
attributes to create a volume with the desired characteristics):
# vxassist [-g diskgroup] make volume length layout=layout \
logtype=dco [ndcomirror=number] [dcolen=size] [fastresync=on] \
[other attributes]
For non-layered volumes, the default number of plexes in the mirrored DCO volume
is equal to the lesser of the number of plexes in the data volume or 2. For layered
volumes, the default number of DCO plexes is always 2. If required, use the
ndcomirror attribute to specify a different number. It is recommended that you
configure as many DCO plexes as there are data plexes in the volume. For example,
specify ndcomirror=3 when creating a 3-way mirrored volume.
The default size of each plex is 132 blocks unless you use the dcolen attribute to
specify a different size. If specified, the size of the plex must be a multiple of 33 blocks
from 33 up to a maximum of 2112 blocks.
By default, FastResync is not enabled on newly created volumes. Specify the
fastresync=on attribute if you want to enable FastResync on the volume. If a DCO
object and DCO volume are associated with the volume, Persistent FastResync is
enabled; otherwise, Non-Persistent FastResync is enabled.
3. To enable DRL or sequential DRL logging on the newly created volume, use the
following command:
# vxvol [-g diskgroup] set logtype=drl|drlseq volume
For more information, see the vxassist(1M) and vxvol(1M) manual pages.
If you use ordered allocation when creating a mirrored volume on specified storage, you
can use the optional logdisk attribute to specify on which disks dedicated log plexes
should be created. Use the following form of the vxassist command to specify the disks
from which space for the logs is to be allocated:
# vxassist [-g diskgroup] -o ordered make volume length \
layout=mirror logtype=log_type logdisk=disk[,disk,...] \
storage_attributes
If you do not specify the logdisk attribute, vxassist locates the logs in the data plexes
of the volume.
For more information about ordered allocation, see “Specifying Ordered Allocation of
Storage to Volumes” on page 205 and the vxassist(1M) manual page.