VERITAS Volume Manager 3.1 Administrator's Guide

Volume Manager Operations
Performing Online Backup
Chapter 3 95
The online backup procedure is completed by running the vxassist
snapshot command on a volume with a SNAPDONE mirror. This task
detaches the finished snapshot (which becomes a normal mirror), creates
a new normal volume and attaches the snapshot mirror to the snapshot
volume. The snapshot then becomes a normal, functioning mirror and
the state of the snapshot is set to ACTIVE.
If the snapshot procedure is interrupted, the snapshot mirror is
automatically removed when the volume is started.
Use the following steps to perform a complete backup using the
vxassist command:
Step 1. Create a snapshot mirror for a volume with the following command:
# vxassist snapstart volume_name
Step 2. When the snapstart step is complete and the mirror is in a SNAPDONE
state, choose a convenient time to complete the snapshot task. Inform
users of the upcoming snapshot and ask them to save files and refrain
from using the system briefly during that time.
Create a snapshot volume that reflects the original volume with this
command:
# vxassist snapshot volume_name temp_volume_name
Step 3. Use fsck (or some utility appropriate for the application running on the
volume) to clean the temporary volume’s contents. For example, use this
command:
# fsck -y /dev/vx/rdsk/ temp_volume_name
Step 4. Copy the temporary volume to tape, or to some other appropriate backup
media.
Step 5. Remove the new volume with this command:
# vxedit -rf rm temp_volume_name