HP StoreServ Application Suite for Oracle Media Virtual Copy Policy, Database Rollback Utility

Recovery Manager for Oracle User’s Guide

2.8 Virtual Copy Policy

3PAR Recovery Manager provides the capability to limit the maximum number of virtual copies allowed per database instance at any time.

For example, a policy can be set to only allow twelve virtual copies at any time for a database. Recovery Manager always maintains the twelve latest virtual copies by removing the oldest virtual copy before creating a new copy. The default, and maximum allowed, number is 500, meaning that up to 500 read-only virtual copies can be created if you have sufficient snapshot space.

2.9 Database Rollback from a Virtual Copy

When a database is corrupted, you can restore the database to the most recent database images from the most recently created virtual copy by using the rollback utility.

2.9.1 The Database Rollback Utility

3PAR Recovery Manager’s database rollback utility (vcdba_rollback) promotes a virtual copy's volumes back to its base virtual volumes. In other words, the base virtual volumes used by the database are rolled back to the virtual copy volumes. Once the rollback process completes successfully, the base virtual volumes are exactly the same as the virtual copy volumes. If the base volume size has been changed since the virtual copy was taken, the rollback process will not affect the new size.

■When rolling back from an online virtual copy, both datafile and archive log virtual volumes are rolled back by default. Use the -ooption to rollback only datafile virtual volumes or only archive log virtual volumes.

■When rolling back from an offline virtual copy, only datafile virtual volumes are rolled back.

■When rolling back from an archive log virtual copy, only archive log virtual volumes are rolled back.

The following restrictions apply when rolling back a virtual copy:

■The online redo logs and control file should not reside on the same virtual volumes used by the datafiles and archive logs. Otherwise, they will be rolled back along with the datafile and archive log virtual volumes.

Virtual Copy Policy

2.15