Snapshot; Figure 79: Snapshot Concept - Accusys ExaSAN A08S3-PS User Manual

4.1.2.8.5 Snapshot

A snapshot is initialized with a data sync task running in the background to duplicate the data
from a source to a target. The host I/O data is also replicated in the target. The mirror snapshot
is offered by the ExaSAN RAID controller.
Note
The source and target volume of the snapshot must be identical.
Before setting a snapshot, you need to set the slice in the array. The capacity of each slice and
the number of shots should be in accordance with the space you need.
Suppose that an array has the capacity of 30 TB, you may divide it into three slices of 10TB.
You must set the LUN map for the first slice. Setting the LUN map for the other two slices is not
required.
In the figure above, a snapshot can be created by splitting the source and target after the
background sync is completed. The I/O mirroring is stopped, and the difference is under
tracking in a bitmap table to support fast re-sync.
User Guide

Figure 79: Snapshot concept

4. How to Use
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