HP 3PAR Application Software Suite for Oracle - Manual (Page 18)

If a Virtual Copy has been backed up, the remove repository utility command fails unless the -f
option is used.
Virtual Copy Policy
HP 3PAR Recovery Manager Software for Oracle provides the capability to limit the number of
Virtual Copies per database at any time. This can be achieved in two ways. One way is to use a
time-based policy, which is based on the expiration time (the Virtual Copy is removed automatically
by an internal scheduler once the expiration time is reached) of the Virtual Copy . The second way
is to use a numeric-based policy, which is based on the maximum number of Virtual Copies specified
in the configuration file (the maximum allowed value is 500).
For a numeric-based policy example, a policy can be set to only allow twelve Virtual Copies at
any time for a database. Recovery Manager for Oracle always maintains the twelve latest Virtual
Copies by removing the oldest Virtual Copy before creating a new copy. If a Virtual Copy is
protected by retention time, it can only be removed after the retention time ends. 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.
For a time-based policy example, if the expiration time is one month (specified in the configuration
file), then the Virtual Copy that reaches the expiration time will be removed from the HP 3PAR
StoreServ Storage system automatically. The system has all the Virtual Copies for last month.
Expiration time can be changed using the rmora_set command.
Database Rollback from a Virtual Copy
When a database is inconsistent, you can restore the database to the most recent database images
from the most recently created Virtual Copy by using the rollback utility.
The Database Rollback Utility
The database rollback utility (rmora_rollback) of HP 3PAR Recovery Manager Software for
Oracle promotes the volume of a Virtual Copy 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 -o option to rollback only datafile virtual volumes or only
archive log virtual volumes.
•
When rolling back from an offline or datafile 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.
•
The database instance must be CLOSED for this operation. If the database is an RAC database,
all RAC instances must be CLOSED.
•
The base (datafile and/or archive log) virtual volumes must be temporarily removed from the
original database server.
NOTE: For detailed instructions and examples for using the rollback utility, see “Using the Recovery
Manager Rollback Utility” (page 117) .
18 Overview of Recovery Manager Operations