VERITAS Storage Foundation 4.1 Intelligent Storage Provisioning Administrator's Guide

Changing the Stripe Unit Size of Volumes
66 VERITAS Storage Foundation ISP Administrator’s Guide
volume. These file system types cannot be shrunk. This restriction does not apply to an
Online JFS (Full VxFS) file system, which can be shrunk while mounted. See the
vxresize(1M) manual page for more information.
Changing the Stripe Unit Size of Volumes
To change the stripe unit size of a striped or RAID-5 volume, use the following command:
# vxvoladm [-g diskgroup] [-b] setstwidth volume stripeunit=size \
[tmplen=length] [attributes...]
If specified, the -b option changes the stripe width in the background.
Note This operation creates a temporary 2-way mirror volume that requires at least two disks, and
therefore twice as much disk space as the size of the temporary volume. The size of the
temporary volume is based on the size of the volume that is being changed. If required, you
can use the tmplen attribute to specify the size of the temporary volume.
For example, the following command changes the stripe unit size of the volume vol1 to 32KB:
# vxvoladm -g mydg -b setstwidth vol1 stripeunit=32k
Adding Logs to a Volume
To add logs to a volume, use the following command:
# vxvoladm [-g diskgroup] [-b] add log volume logtype=type \
[nlogs=number] [loglen=length] [attributes...]
The supported log types are dcm, dco, drl and raid5.
Adding a data change object (DCO) and DCO plex to a volume also allows the use of instant
snapshots and dirty region logging (DRL) with the volume.
Traditional DRL may be added by specifying logtype=drl instead of logtype=dco. Such
logs are implemented using a dedicated plex for each log copy, rather than using a DCO volume,
and are supported for mirrored volume layouts only.
Data change map (DCM) logs are used with VERITAS Volume Replicator (VVR) replicated
volumes. This type of log is usually added automatically by VVR adminstration commands.
RAID-5 logs are supported for software RAID-5 volumes only.
By default, one log or a DCO with one plex is added. You can use the nlogs attribute to specify
the number of logs or DCO plexes to add. The loglen attribute can be used to specify the size of
a RAID-5 log or a DCO volume. If the volume already contains such a log or DCO volume, this