4
What Is EMC SnapView Software?
4-3
About SnapView Snapshot Copy Software
Figure4-1 SnapView Operations Model
SnapView offers several important benefits:
•It allows full access to production data with minimal impact on
performance;
•For decision support or revision testing, it provides a coherent,
readable and writable copy of real production data at any given
point in time; and
•For backup, it practically eliminates the time that production data
spends offline or in hot backup mode. And it off-loads the backup
overhead from the production host to another host.
Snapshot Components
A snapshot session uses three components: a production host, a
second host, and a snapshot copy session.
•The production host runs the customer applications on the LUN
that you want to copy, and allows the management software to
create, start, and stop snapshot sessions.
•The second host reads the snapshot during the snapshot session,
and performs analysis or backup using the snapshot.
•A snapshot session makes the snapshot copy accessible to the
second host; it starts and stops according to directives you give
using Navisphere software on the production host.
EMC1822
Continuous
I/O
The snapshot is a composite
of source LUN and cache
data that is accessible as
long as the session lasts.
Storage system
Snapshot
Snapshot
cache
Source
LUN
Production
host Second
host