Veritas FlashSnap Point-In-Time Copy Solutions 5.0 AdministratorÆs Guide, HP-UX 11i v3, First Edition, May 2008

33Online database backup
Making a backup of an online database on the same host
Note: It is assumed that you have already prepared the volumes containing the
file systems for the datafiles to be backed up as described in “Setting up volumes
for instant snapshots” on page 21. For an Oracle database, it is not necessary to
create snapshots of the volumes containing the file systems for the redo log
volumes or archived logs.
To make a backup of an online database on the same host
1 Use the following commands to add one or more snapshot plexes to the
volume, and to make a full-sized break-off snapshot, snapvol, of the
tablespace volume by breaking off these plexes:
# vxsnap -g volumedg addmir volume [nmirror= N ] \
[alloc=
storage_attributes ]
# vxsnap -g
volumedg make \
source=
volume /newvol= snapvol [/nmirror=N]\
[alloc=
storage_attributes ]
By default, one snapshot plex is added unless you specify a number using
the
nmirror attribute. For a backup, you should usually only require one
plex. You can specify storage attributes (such as a list of disks) to determine
where the plexes are created.
If the volume layout does not support plex break-off, use the procedure
described in “Creating a volume for use as a full-sized instant snapshot” on
page 27 to prepare an empty volume for the snapshot, and then use the
following command to create the snapshot:
# vxsnap -g volumedg make source= volume /snapvol= snapvol
If a database spans more than one volume, specify all the volumes and their
snapshot volumes as separate tuples on the same line, for example:
# vxsnap -g dbasedg make source=vol1/snapvol=svol1 \
source=vol2/newvol=svol2 source=vol3/snapvol=svol3
If you want to save disk space, you can use the following command to create
a space-optimized snapshot instead:
# vxsnap -g volumedg make \
source=
volume /newvol= snapvol /cache= cacheobject
The argument cacheobject is the name of a pre-existing cache that you have
created in the disk group for use with space-optimized snapshots. See
“Creating a shared cache object” on page 28 for more information.
If several space-optimized snapshots are to be created at the same time,
these can all specify the same cache object as shown in this example:
# vxsnap -g dbasedg make \
source=vol1/newvol=svol1/cache=dbaseco \
source=vol2/newvol=svol2/cache=dbaseco \
source=vol3/newvol=svol3/cache=dbaseco