4
What Is EMC SnapView Software?
4-3
About SnapView Snapshot Copy Software
Figure 4-1 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
