Using ContinuousDataReplicator with Oracle

The following section provides the steps required to use CDR for data replication and recovery of Oracle data based on a single source and single destination. If your environment uses a different scenario, adjust your steps accordingly.

Before You Begin

• A full understanding of the following subjects will prove helpful:
  • Overview - ContinuousDataReplicator
  • Data Replication
  • Application Integration
  • Recovery Points
  • Recover Replicated Data

Data Replication and Consistent Recovery Points for Oracle

Required Capability: Capabilities and Permitted Actions

To use CDR to replicate Oracle data and create Consistent Recovery Points:

1. Select two computers on which to install CDR, one designated as the source computer, and one designated as the destination computer.
   • Verify that they both meet the System Requirements.
   • Install the ContinuousDataReplicator software on both computers.
2. Consistent Recovery Points can only be created for Oracle if the database and archive logs are not on the same volume on the source computer (the production server.) The archive logs can be in more than one location, as long as none of them is on the same volume as the database. If necessary, use the Oracle ALTER command to set the archive log location to a different volume. For example:

   ALTER SYSTEM SET LOG_ARCHIVE_DEST_10 = 'LOCATION=F:\ORALOG1';

3. If you are using QSnap, consider the following:
   • To use QSnap with CDR on UNIX, before you can begin creating Replication Sets and Replication Pairs, you must first configure source and destination volumes as CXBF devices. For more information, see QSnap for ContinuousDataReplicator.
   • For VSS, you may want to use separate volume for shadow storage.
4. Configure CDR to Replicate Application Data.
5. Create a Replication Set.
6. Configure Consistent Recovery Points for the Oracle data; see Configure CDR Recovery Points.
7. Add a Replication Pair. The database itself, as well as all Oracle log destinations, e.g., archivelog_dest1, archivelog_dest2, etc., must be replicated to ensure that a Copyback operation can succeed. When you use the Add App button during Replication Pair creation, all log file location will be discovered, and all necessary Replication Pairs will be created.
8. Start Data Replication Activity.
9. Create a Consistent Recovery Point Using CDR. Each Consistent Recovery Point for a given Oracle database will comprise two snapshots:
   • The first snapshot will include all Oracle data volumes.
   • The second snapshot will include all Oracle log volumes and backup control file for the database at the time the Consistent Recovery Point was created.

   • If Replications Pairs for Oracle log and database replication are configured to use the same destination volume, the actual number of Recovery Points retained will be the number specified in Maximum Number of Recovery Points divided by two, because separate snapshots will be created for the logs and the database. For example, if you have specified 10 as the maximum number of Recovery Points, but use the same destination volume for the logs and database, only 5 Recovery Points will be retained, with 2 snapshots in each.

Additional Recommendations

• On both the source and destination computers, it is recommended that you Configure Throttling for CDR Replication Activities.
• It is recommended that you Configure Alerts. For more information, see Alerts.

  It is also recommended that you also see Space Check for the Quick Recovery and ContinuousDataReplicator Agents and configure the Disk Space Low alert to provide warning that the source computer is running out of disk space, which will ultimately cause replication activity to be System Aborted.

• It is recommended that you do not configure Oracle log and database to use the same destination volume.
• Optionally, you can Configure CDR for Backups of Recovery Points.

  To perform backups of Recovery Points, you must also install either the Windows File System iDataAgent on both the source and destination computers, or the Unix File System iDataAgent on both the source and destination computers. You cannot replicate Windows data to a UNIX computer, nor the converse.

• Monitor Data Replication Activities.
• View the Recovery Point Creation History.
• Run and review the CDR Replication Job Summary Report.

Copyback of Oracle Data

Oracle data is restored at the database level. While you can restore Oracle data from a Recovery Point, a backup of a Recovery Point, or the Live Copy, these methods will not ensure consistency of the application data; only a restore from a Consistent Recovery Point, or a backup of one, will ensure consistency of application data. A Consistent Recovery Point is recommended as the source when moving replicated data back to the production Oracle server. To ensure application integrity, you must use Add App to create your Replication Pairs. (Refer to Add or Edit a Replication Pair and Application Integration.) Add App discovers the location of all user-defined and system databases on the client, which you can select for data replication.

For step-by-step instructions, see Copy Back Oracle Data from a Consistent Recovery Point.

For Unix, sparse files attributes are not retained during Copyback, neither from a Live Copy nor a Recovery Point; the files assume the attributes of regular files on the recovery host.

Additional Recommendations

• View the Recovery Point Copyback History.
• Run and review the CDR Copyback Job Summary Report.