VXVM dirty region logs

[andrew medhurst]

Hi guys
I have am interesting issue, it is that i have just built a new server to replicate a current production server.
the server is mainly a sybase Database server and has approx 130 raw disk volumes.
i have now been asked by stake holder (having himself just read veritas professional document)to turn on DIRTY REGION LOGS.
can this be done on already set up volumes and if so how( hopefully easily)
regards
andrew

[Robert-Jan Goossens · Accepted solution]

Hi,

This can be done on an excisting volume (vxfs).

link to the URL
http://ftp.support.veritas.com/pub/support/products/VolumeManager_UNIX/vm32_admin_240253.pdf

Adding DRL Logging to a Mirrored Volume
To put dirty region logging (DRL) into effect for a mirrored volume, a log subdisk must be
added to that volume. Only one log subdisk can exist per plex.
To add DRL logs to an existing volume, use the following command:
# vxassist addlog volume logtype=drl [nlog= n]
The nlog attribute can be used to specify the number of log plexes to add. By default, one
log plex is added. For example, to add a single log plex for the volume vol03, use the
following command:
# vxassist 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 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 same procedures as are used to remove ordinary plexes and subdisks.

Regards,
Robert-Jan