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RE: RMAN without a repository

From: Robert Freeman <>
Date: Thu, 12 Apr 2007 23:45:13 -0600
Message-ID: <>

Couple of things:

  1. In 10g Oracle allows you to catalog backup set pieces. So even if a backup set piece is inadvertently dropped from the control file, you can just recatalog it and voila, it's available for a restore. You can also recatalog an entire directory which is most helpful in certain control file recovery cases. See Oracle Database 10g RMAN Backup and Recovery for more on this cool feature!!
  2. Even with the control file record keep time set to 365 days, there is a point at which the control file will not be able to grow and you will start loosing records. I don't recall the exact size or particulars of this, but you will start seeing errors in the alert log. I kind of like Oracle's suggestion to this problem.... NOT:

If the control file is at the maximum size supported under the host operating system, then the database cannot expand the control file. In such a situation, this warning appears in the alert log:

WARNING: Oracle Managed File filename is unknown to control file. This is the result of limitation in control file size that could not keep all recovery area files.

This means that the control file cannot hold a record of all flash recovery area files needed to satisfy the configured retention policy.

There are several ways to avoid or alleviate this problem:

  a.. Use a control file of larger block size, preferably one with 32K block size. To achieve this, you must set the SYSTEM tablespace block size to be greater than or equal to the control file block size, and re-create the control file after changing DB_BLOCK_SIZE.

  b.. Make the files in the flash recovery area eligible for deletion, by backing them up to tertiary storage such as tape. For example, you can use the RMAN command BACKUP RECOVERY AREA to specifically back up files in the flash recovery area to your media manager.

  c.. Make more files in the flash recovery area eligible for deletion, by changing the retention policy to a shorter recovery window or lower degree of redundancy.

Robert G. Freeman
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Principle Engineer/Team Manager
The Church of Jesus Christ of Latter-Day Saints Collaborate '07
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  -----Original Message-----
[]On Behalf Of   Sent: Tuesday, April 10, 2007 1:40 PM
  Subject: RMAN without a repository

  If I am making tape backups and I am using redundancy 4. How do I restore older backups after the controlfile recycles? Or do I set control_file_record_keep_time to a sufficiently large number?

  do I have to write down the DBID and use that to restore an older copy?

Received on Fri Apr 13 2007 - 00:45:13 CDT

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