Veritas Storage Foundation™ for Oracle 5.0.1 Administrator's Guide

Note: In Oracle RAC configurations, only the online option can be used.
How to plan for Database FlashSnap
Before using Database FlashSnap, you must determine your intended application.
You then need to make the following decisions:
■ Which snapshot mode is appropriate: online, offline, or instant?
Veritas Storage Foundation for Oracle RAC uses only the online mode.
■ Will you need one or two hosts?
Snapshot mode
If your purpose is to use the snapshot for backup or to recover the database after
logical errors have occurred, choose the online option. In the event that your
production database is offline, choose offline. If you intend to use the snapshot
for decision-support analysis, reporting, development, or testing, choose instant.
An instant snapshot is not suitable for recovery because it is not necessarily an
exact copy of the primary database.
With Veritas Storage Foundation for Oracle RAC, you do not select a snapshot
mode because only the online mode is used.
One or two snapshot hosts
If maintaining the performance of your primary database is critical, you can
offload processing of the snapshots to a secondary host. For off-host processing,
storage must be shared between the primary and secondary hosts.
If cost savings is most important, you can choose to do the processing on the same
host as the primary database to save on hardware costs.
Hosts and storage for Database FlashSnap
Database FlashSnap requires sufficient Veritas Volume Manager disk space, and
can be used on the same host that the database resides on (the primary host) or
on a secondary host.
With Veritas Storage Foundation for Oracle RAC, Database FlashSnap can be used
on the same cluster that the database resides on.
229Using Database FlashSnap for backup and off-host processing
How to plan for Database FlashSnap