User`s manual

SAS / SATA II NAS System
118
User’s Manual
8.1.3 Volume Snapshot
Snapshots are point-in-time copies of a logical volume. This allows the system
administrator to create a new block device which presents an exact copy of a logical
volume, frozen at some point in time. As changes are made to the original volume, the
snapshot remains the same and looks exactly like the original at the time the snapshot
was created.
A Snapshot can be created manually or scheduled. Admin need to enable first this
special function.
NOTE: Logical Volume with snapshot cannot be extended nor
replicated (see next section about Volume Replication).
To enable Snapshot function, select Volume Manager then click Options tab. Tick the
“Enable Snapshot function” option.
NOTE: Creating Snapshots while a Logical Volume is under heavy
I/O will slowdown the I/O access or interrupt the I/O process to a
Logical Volume. This means that clients accessing the proNAS
share, in which the Logical Volume is under snapshot, can
experience slow write access.