Questions regarding Backup/Recovery of Oracle database

[mdecker77]

Hello Forum,

I am researching the topic of Backup/Restore of Oracle with Veeam B&R for VMWare and am looking for documentation material. I have made myself familiar with the Oracle VSS Writer documentation and checked veeam documentation, but in there I can not find any information specific to Oracle.

We have performed a test backup of an archivelog database with snapshot backup and we can see the interaction of Veeam/VSS/Oracle. We have enabled trace file for Oracle VSS writer.

I have several questions:
1) for the restore/recovery we can not find any information in the oracle VSS Logfile. Is VSS relevant for restore/recovery of oracle databases?
2) will the backup fail of there is a problem with Oracle VSS operations or is there a risk that the backup runs successfully without VSS and the database can not be restored correctly?
3) how would we restore not the complete virtual machine but only the database or only parts of the database? would we just restore the relevant files? Will this trigger Oracle VSS operations?

Regards,
Martin

[veremin]

2) Will the backup fail of there is a problem with Oracle VSS operations or is there a risk that the backup runs successfully without VSS and the database can not be restored correctly?

In the advanced "Guest Processing" settings of a given job, you can tick option called “Require successful application processing. This should guarantee that job won’t proceed, if Oracle database hasn’t been successfully quiesced.

Also, it might be worth utilizing SureBackup functionality in order to verify recoverability of the backups. Thanks.

[foggy]

3) how would we restore not the complete virtual machine but only the database or only parts of the database? would we just restore the relevant files? Will this trigger Oracle VSS operations?

Yes, you should use File-Level Restore functionality to restore database files from the VM backups. No way to restore database partly other than using Instant Recovery, connect to the recovered VM using native Oracle tools and extracting the required data from the database. VSS is not engaged in the restore process.

[Vitaliy S.]

Hello Martin,

1) for the restore/recovery we can not find any information in the oracle VSS Logfile. Is VSS relevant for restore/recovery of oracle databases?

VSS is relevant for Oracle databases starting from 11g version, so please do enable application-aware image processing if applicable. As to the log files processing, then please see this quote from Tom Sightler, our solutions architect:

Oracle does not really use log truncation in the same way that SQL does. Oracle is generally configured to keep a fixed number of "online" redo log files. These logs will simply rotate between each other in a circular fashion. To facilitate point-in-time recoveries the database may be configured for "archive log" mode. In this mode immediately after a log switch (when the "active" log is moved to the next online log file in the rotation) a copy of the previous log is "archived" into an alternate location.

Generally you control the number of archive logs via RMAN backups, either using native RMAN tools, or third-party tools that integrate with RMAN. However, they can also simply be purged manually. For example, if you only want to keep 3 days worth of archive logs (thus allowing you to restore a database backup from the previous 72 hours and then recover to any point-in-time in that window) you simply write a script that runs once a day (or an hour or whatever) and removes all logs older than the specified timeframe.

It of course would be possible to trigger this from a post-job script if desired, but typically this is not really required since you're generally deciding how many "days" worth of archive logs to keep online at any time.

If the customer does not care about point-in-time recovery then they should simply not use archive log mode and then there aren't any logs to purge at all. This is basically the equivalent of MS SQL's "simple" recovery model.

Thank you!