Recovering the database using the split-mirror snapshot and database logs

The following figure shows the situation where there has been a database failure. The snapshot volume is located on the right. The arrow pointing back to the production database volume represents the recovery of the database using the snapshot and applying the logs to bring the database to the level just before the failure occurred.

Figure: Database recovery from a snapshot

Database recovery from a snapshot

Note:

This example uses a single snapshot of the datafile of the tablespace of an Oracle database. It could also be done by using multiple, simultaneous snapshots that include both the data file and the log.

To simulate Oracle datafile corruption

  1. In Oracle Enterprise Manager, take the tablespace offline.
  2. Use Windows Explorer to locate and open the datafile volume.
  3. Delete the datafile.

To recover the Oracle datafile

  1. In Oracle, take the datafile offline.
  2. In the VEA GUI, click the Snap Back button to reattach the snapshot volume, and use the Resynchronize using the snapshot option.
  3. In Oracle, use RECOVER TABLESPACE to apply the database logs to bring the replica to the level just before the datafile corruption occurred.
  4. In Oracle, bring the datafile online.
  5. Verify that the tablespace in the datafile has been recovered.