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To preface... I have mentioned this before in a previous question, but I'll add it again: Our Senior Oracle DBA has just recently passed away, and I've been taking over. My level of experience is just a junior level. So there is a lot I still don't understand. So I appreciate all the tips I can get, as this is a very frightening position for me.

My Question... Our sys admins created a new filesystem for our RMAN backups, I believe we are only running FRA backups in the original directory. I would first like to ask, what should I look out for before I change the DB_RECOVERY_FILE_DEST parameter value? Is there anything that could possibly be affected aside from the location change? We also have Standby databases, just to add any further detail.

Secondly, what else am I supposed to do besides changing the DB_RECOVERY_FILE_DEST parameter value? Are there additional steps?

Finally, how should I move my previous backups from the old location to the new?

2 Answers 2

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You don't need to, and shouldn't, move the existing backups from the old FRA. When a backup, or an archivelog file, is written, it's absolute location is recorded in the repository in the db control file, and in the rman catalog, if used. If those backups are needed, the control file will be consulted to see where they are, and as noted that will point to their original location. If you move them they will no longer be where the repository says they are. There are ways to overcome that, but it's easier to leave them alone. Just continue to take backups and confirm that they (the new backups) are being written to the new FRA. Also be sure that your back scripts include the rman command DELETE OBSOLETE. This will cause the backups in the older FRA to be cleaned out as they are no longer needed.

There are some other 'gotchas', but it would be best to see your backup scripts, and the output of rman SHOW ALL command to see what might be addressed.

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  • The only reason we need to move our backups is because we are relinquishing the space in the original filesystem due to a storage capacity issue. How can I find the backup scripts? I believe they are already deleting obsoletes.
    – Phillip
    Jun 21, 2021 at 19:25
  • How to find the backup scripts? Umm. Look at whatever mechanism is used to schedule them. Unless you have a really long retention period/recovery window, I'd still advise just waiting until the old backups roll off. With the usual 7 day recovery window and a full backup once a week, it would take two weeks at the most. Surely the project can wait that long.
    – EdStevens
    Jun 21, 2021 at 19:31
  • As an aside, I sympathize with your position of having this dumped in your lap. Keep in mind that the DBA's "Prime Directive" is "Do not lose data". To that end, your first priority needs to be learning how your backups are scheduled, where the scripts are located, and thoroughly understanding every line of the scripts, as well as every line of the output of rman 'SHOW ALL' command. And management needs to understand the difficult position you've been put it.
    – EdStevens
    Jun 21, 2021 at 19:34
  • At some point last week, the original filesystem filled to full capacity and stopped recording backups. So as I understand, this is a very severe risk of data loss. I was able to clear up the filesystem a little bit but it is on the verge of filling up again until I move everything. So this is a big part of why I'm attempting to move old backups as soon as possible. But if you still insist on waiting until these backups expire, then I will. Let me know.
    – Phillip
    Jun 21, 2021 at 19:40
  • Ok, it sounds like getting them moved is time critical. Move them with the relevant OS commands, the let rman know where they are by using the rman CATALOG command (look it up). After you have confirmed they are moved and known to oracle in their new location (rman LIST BACKUP), you can delete the originals, then let oracle know about that with rman CROSSCHECK, followed by DELETE EXPIRED. Look up the details. The CROSSCHECK checks that the backups recorded in the repository are where they are supposed to be. If not, the records are marked 'expired'.
    – EdStevens
    Jun 21, 2021 at 20:22
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DB_RECOVERY_FILE_DEST controls the location of the Fast Recovery Area, in which Oracle places several files, or copies of files - not just RMAN backups - automatically. Be sure that everything is being sent to the new location; do not delete any backups or other files from the old location until you are sure they are obsolete, and have been replaced in the new location. Also consider the parameter DB_RECOVERY_FILE_DEST_SIZE parameter, as you may need to increase that to allow for proper use of your new space.

See here for more info:

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  • When I move the old backups, is it a simple Linux cp/mv/rsync commands? Or is there an RMAN command that moves these?
    – Phillip
    Jun 21, 2021 at 18:07
  • RMAN tracks all backup files in it's own registry. You need to use RMAN commands to change anything; don't just do it at the file system.
    – pmdba
    Jun 21, 2021 at 18:45
  • What are the RMAN commands to move all the FRA files? I can't find this in the documentation.
    – Phillip
    Jun 21, 2021 at 18:51
  • Also, a follow-up, does this task require rebooting the database?
    – Phillip
    Jun 21, 2021 at 19:12
  • See Ed Stevens' answer. Best to just leave those files alone until they expire, then remove them during your normal backup operation. A restart is required before Oracle will fully use the new FRA.
    – pmdba
    Jun 21, 2021 at 19:21

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