Veritas Storage Foundation™ 5.0.1 for Oracle RAC Installation, Configuration, and Administrator's Guide Extracts for the HP Serviceguard Storage Management Suite on HP-UX 11i v3

NOTE: dbed_vmclonedb does not support instant snapshot for database cloning.
All of these commands can be executed by the Oracle database administrator and do not require
superuser (root) privileges.
NOTE: Database FlashSnap operations can be executed from the command-line.
Using Database FlashSnap Options
Database FlashSnap offers three options for creating database snapshots. The option you choose
is specified in the snapplan.
• online
With this option, the tablespaces are put into online backup mode before the snapshot is
created. This type of snapshot is also a valid database backup. Select this option if you are
performing a point-in-time recovery from logical errors.
• instant
With this option, the database can be up and running, and the tablespaces do not need to
be put into online backup mode before the snapshot is created. However, all the file systems
used by the database (including those containing the online redo logs and control files) are
temporarily frozen and the cache is flushed before the snapshot is created. By freezing the
file systems, the snapshot will be a consistent point-in-time image of the database from
which a database clone can be created.
An instant snapshot can be used to guard against data corruption or for off-host
decision-support queries. However, it is not a valid database backup and cannot be used to
perform a point-in-time recovery or off-host backup since tablespaces are not put into online
backup mode before the snapshot is created. The instant option is much faster than the
online option.
• offline
The offline option can be used to clone or back up a database. With this option, the database
must be shut down when the snapshot is created and online redo logs are required. This
type of snapshot is a valid database backup.
In this release of HP Serviceguard for Oracle RAC, Database FlashSnap supports third mirror
break-off snapshots only. Third mirror break-off snapshots are fully synchronized, full-sized
snapshots.
Planning to Use Database FlashSnap
Before using Database FlashSnap, you must first determine your intended application. You will
then need to make the following decisions:
• Which snapshot mode is appropriate: online, offline, or instant?
• Will you need one or two hosts?
Selecting the 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.
52 Using FlashSnap for Backup and Recovery