APC RAID Subsystem SCSI-SATA II - Manual (Page 73)

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Figure 4.3.1
Figure 4.3.2
(Figure 4.3.2: Extend UDV-R0 from 5GB to 10GB.)
4.4 Snapshot /Rollback
IS16GL Snapshot-on-the-box captures the instant state of data in the target
volume in a logical sense. The underlying logic is Copy-on-Write -- moving out
the to-be-written data to certain location whenever a write action occurs since the
time of data capture. The certain location, named as snap UDV, is essentially a
new UDV,.which can be attached to a LUN thus provisioned to a host as a disk
just like other ordinary UDVs in the system. Rollback function restores the data
back to the state of any point in time previously captured for whatever
Tips
The size of UDV extension must be larger than original.
Caution
UDV Extension cannot be executed during rebuild or migration.