A SERVICE OF

logo

71Understanding Veritas Volume Manager
FastResync
Figure 1-32 Mirrored volume with persistent FastResync enabled
To create a traditional third-mirror snapshot or an instant (copy-on-write)
snapshot, the
vxassist snapstart or vxsnap make operation respectively is
performed on the volume. This sets up a snapshot plex in the volume and
associates a disabled DCO plex with it, as shown in Figure 1-33.
Figure 1-33 Mirrored volume after completion of a snapstart operation
Multiple snapshot plexes and associated DCO plexes may be created in the
volume by re-running the
vxassist snapstart command for traditional
snapshots, or the
vxsnap make command for space-optimized snapshots. You
can create up to a total of 32 plexes (data and log) in a volume.
Mirrored volume
Data plex
DCO volume
Data plex
Data change object
DCO
DCO
plex
plex
Mirrored volume
Data plex
DCO volume
Data plex
Data change object
DCO
DCO
plex
plex
Snapshot
plex
Disabled
DCO
plex