Oracle and TSM for Databases: Part 1

Posted by on Feb 15, 2011 in Databases, Storage, TSM | 5 Comments

One of the most confusing areas for TSM admins is backing up Oracle databases using TSM for Databases (frequently referred to by its old name, Tivoli Data Protection or TDP).  In this series, I’ll provide an overview of how to use TSM to backup Oracle databases, with a special emphasis on problems you may face as the TSM admin.

What makes backing up Oracle through TSM difficult is the complex nature of Oracle backups.  Rather than TSM managing the backups, the Oracle backup utility, RMAN, performs this function.  And since RMAN manages its own backups, most of the typical methods and knowledge known by TSM admins do not apply.  You’ll need to work with your DBA to develop a backup scheme, and also to impart some knowledge of how TSM interacts with RMAN.

TDP and BA clients

In addition to the standard, backup-archive (BA) client used to backup the system, backing up an Oracle database also requires a second, licensed client, the Tivoli Data Protection (TDP) client. The TDP client allows RMAN to use TSM as what Oracle calls the “media management layer” (MML).  The TDP client is registered as a separate node on the TSM server, so that its backups are segregated, and can (and probably should) have different management policies.

Catalog and Control files

Not using a catalog server is probably the biggest source of headaches when using TDP.  A catalog server is simply a separate Oracle database, which has a schema that contains backup metadata.  When doing backups, restores, or other maintenance, RMAN connects to the catalog server and manages the metadata.  The upshot is that this provides a record of database backup objects that are not stored with the instance being backed up.  The downside is that it is another Oracle database to manage.

When not using the catalog server, you are using the database control files. Basically what both are doing is keeping track of the location of your backups. The problem with control files is that they are much more limited in the number of backup objects they can reference, so you lose reference to things. So the main worry is not that you are using so many tapes, it’s that you cannot restore what you have backed up. Sure, TSM has all the Oracle backups, but Oracle doesn’t know they’re there.

So, if you are not using a catalog server, then it’s safe to say that you are out of sync with TSM.

In the next part, I’ll discuss how you can keep TSM and Oracle in sync.

References

See Getting Started with Recovery Manager (RMAN) [ID 360416.1] on My Oracle Support for more details on RMAN.

See Data Protection for Oracle for UNIX and Linux Installation and User’s Guide and Data Protection for Oracle for Windows Installation and User’s Guide in the TSM Information Center.