Veritas Storage Foundation for Oracle 5.0 Administrator's Guide, HP-UX 11i v3, Second Edition, December 2008

■ You must be logged in as superuser (root).
■ The disk group must be version 110 or later. For more information
on disk group versions, see the vxdg(1M) online manual page.
■ Be sure that a data change object (DCO) and a DCO log volume are
associated with the volume for which you are creating the snapshot.
■ Persistent FastResync must be enabled on the existing database
volumes and disks must be assigned for the snapshot volumes.
FastResync optimizes mirror resynchronization by tracking
updates to stored data that have been missed by a mirror. When
a snapshot mirror is reattached to its primary volumes, only the
updates that were missed need to be re-applied to resynchronize
it. FastResync increases the efficiency of the volume snapshot
mechanism to better support operations such as backup and
decision support. For detailed information about FastResync, see
the Veritas Volume Manager Administrator's Guide.
■ Snapshot mirrors and their associated DCO logs should be on
different disks than the original mirror plexes, and should be
configured correctly for creating snapshots by the system
administrator.
■ When creating a snapshot mirror, create the snapshot on a separate
controller and separate disks from the primary volume.
■ Snapplan validation (dbed_vmchecksnap) fails if any volume in
the disk group is not used for the database.
■ Allocate separate volumes for archive logs.
■ Do not place any datafiles, including control files, in the
$ORACLE_HOME/dbs directory.
Prerequisites
227Using Database FlashSnap for backup and off-host processing
Hosts and storage for Database FlashSnap