Implementing ARCHIVELOG - Any ideas?

[adrianomp]

Scary scenario:
- Production database;
- NOARCHIVELOG;
- Only logical backups;
- "Theoretically" 24x7; cold backups cannot be implemented (one MONTHLY backup MAY be possible);
- No load balancing: all datafiles concentrated on the same RAID5 device
- Disk capacity near the limit;
- No resources or possibility of changing that architecture immediately;

The question is: what is a proper way to force ARCHIVELOG on a scenario like that? some considerations I already made:

- Archiving to a remote server is a bit dangerous; a network failure might impact database activity; anyway, even with no failures network bandwidth should be severely affected.

- Maybe ARCHIVELOG could be implemented on the local disk with an automatic routine to clear archives. However, it would be an extra write activity on a RAID5 device busy enough. It might potentially affect performance.

Any different and creative approaches to workaround that without hardware interventions?

[marist89]

If you're going to archive, you've got to have space. Period.

In your situation, I would plan on a daily hot backup. You could limit the growth of your log_archive_dest by running several archivelog backups to tape or NFS disk throughout the day and removing them once they are backed up. However, not having your archived redo logs on disk will severely limit your chances for a quick recovery.

[marist89]

Originally posted by adrianomp
- Only logical backups;

I won't even touch that one...

[Latyr]

You may think about using RMAN.
You will then alter the database to applied archivelog.
With RMAN you have the availability to perform Hot Backup to tape.
With RMAN you can run a script that backups all the archivelog periodicly and clear them from the disk.

Latyr

[adrianomp]

Originally posted by marist89
In your situation, I would plan on a daily hot backup. You could limit the growth of your log_archive_dest by running several archivelog backups to tape or NFS disk throughout the day and removing them once they are backed up. However, not having your archived redo logs on disk will severely limit your chances for a quick recovery.

Totally agree. However, it may be better to have a "not so quick" recovery than "no recovery" at all. According to my estimates, a full recovery would take 12+ hours.

What about NFS? Based on your experience, would you recommend it? Personally, I had some problems on NFS mounting/umounting due to its persistency nature. Maybe just ignorance of mine, never tried it on Oracle myself.

You may think about using RMAN.
You will then alter the database to applied archivelog.
With RMAN you have the availability to perform Hot Backup to tape.
With RMAN you can run a script that backups all the archivelog periodicly and clear them from the disk.

Oh, I forgot to tell... Not 9i. Not even 8i. I think I'll shoot my head

Our 9i databases already use RMAN with ARCHIVELOG and happilly they aren't an issue for now.

[marist89]

Originally posted by adrianomp
What about NFS? Based on your experience, would you recommend it? Personally, I had some problems on NFS mounting/umounting due to its persistency nature. Maybe just ignorance of mine, never tried it on Oracle myself.

Archiving directly to NFS? Nope, wouldn't do it. NFS and automounter are too flaky to trust to a running database. Backing up to NFS? Sure, I do it every day. If my backup fails because NFS flakes out my database stays up and keeps servicing users. I can always re-run my backup. Just my $.02, though.