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Best Practices for Oracle 11g Backup and Recovery using RMAN and Dell EqualLogic Snapshots

instance database on backup server, you need to remove all RAC related settings from the

database parameter file.

3. Discover the iSCSI targets on the backup server after mounting the snapshots.

4. Login to the iSCSI targets.

5. Discover the Oracle ASM disks using the “oracleasm scandisks” utility. Since the mounted

snapshots are copies of the original database volumes the original ASM labels are available.

6. Perform the steps detailed in section 8.5, Discovering ORACLE ASM disks on the backup

server.

7. Start the Oracle ASM instance and mount the Oracle ASM disk groups.

8. Bring up the single instance database on backup server in the mounted state.

9. Perform an RMAN backup of the database on the backup server.

Recovery

(on the production server):

Before restoring the database, the backup performed on the backup server needs to be registered

in the production database control file. Use the RMAN “catalog backuppiece”

5.4 Performance impact

feature to register

the backup performed on the backup server in the control file of the production database. Once

the backup is registered on the production database, restore and recovery operations can be

performed using RMAN.

Before creating the snapshots of the database volume collection we had to place the database in hot

backup mode to maintain consistency. EqualLogic snapshots are created almost instantaneously.

Therefore, the time that the database needs to be placed in hot backup mode can be very short. After

creating the snapshot collection and taking the database out of hot backup mode. After completing

this process we did not see any performance impact on the production database server while RMAN

backup was reading from the snapshot collection. The net effect of this method is that we were able

to perform RMAN backup and recovery operations without causing any impact on the production

database system resources, other than the short time period during which the database was in hot

backup when creating the snapshot of the volume collection. This method offloads the CPU utilization

impact shown in Figure 4 from the production database server.

5.5 Database complete recovery time

The database was recovered using the recovery procedure explained in section 5.3, Backup and

recovery procedure using EqualLogic snapshots and RMAN.

• Time to restore the database: 50 minutes

• Time to recover the database: 90 minutes

• Total time: 140 minutes

The 200GB database was restored in 50 minutes. The complete recovery operation took 90 minutes.

Reference: Oracle Database Backup and Recovery Reference 11g Release 1:

http://download.oracle.com/docs/cd/B28359_01/backup.111/b28273/rcmsynta008.htm