Veritas Volume Manager 5.0 Administrator's Guide (September 2006)

273Administering volumes
Adding traditional DRL logging to a mirrored volume
To add DRL logs to an existing volume, use the following command:
# vxassist [-b] [-g diskgroup] addlog volume logtype=drl \
[nlog=n] [loglen=size]
Note: If specified, the -b option makes adding the new logs a background task.
The
nlog attribute can be used to specify the number of log plexes to add. By default, one
log plex is added. The loglen attribute specifies the size of the log, where each bit
represents one region in the volume. For example, the size of the log would need to be
20K for a 10GB volume with a region size of 64 kilobytes.
For example, to add a single log plex for the volume vol03, in the disk group, mydg, use
the following command:
# vxassist -g mydg addlog vol03 logtype=drl
When the vxassist command is used to add a log subdisk to a volume, by default a log
plex is also created to contain the log subdisk unless you include the keyword
nolog in
the layout specification.
For a volume that will be written to sequentially, such as a database log volume, include
the logtype=drlseq attribute to specify that sequential DRL is to be used:
# vxassist -g mydg addlog volume logtype=drlseq [nlog=n]
Once created, the plex containing a log subdisk can be treated as a regular plex. Data
subdisks can be added to the log plex. The log plex and log subdisk can be removed using
the procedure described in “Removing a traditional DRL log” on page 273.
Removing a traditional DRL log
Note: The procedure described in this section removes a DRL log that is configured within
a dedicated DRL plex. The version 20 DCO volume layout includes space for a DRL log.
To remove a DRL log, use the
vxassist command as follows:
# vxassist [-g diskgroup] remove log volume logtype=drl [nlog=n]
By default, the vxassist command removes one log. Use the optional attribute nlog=n
to specify the number of logs that are to remain after the operation completes.
You can use storage attributes to specify the storage from which a log is to be removed.
For example, to remove a log on disk mydg10 from volume vol01, enter:
# vxassist -g mydg remove log vol01 !mydg10 logtype=drl