topic Re: backup oracle non-archive database after snapshot with RMAN in Operating System - HP-UX

backup oracle non-archive database after snapshot with RMAN

Richard Kupca — Mon, 30 May 2005 09:02:21 GMT

Hi,

my conf: 2 HP-UX servers in RAC, HP EVA 5000 with business copy, oracle 10g database in non-archive mode (size 5000 GB), RMAN.

I want to backup oracle database after creating snapshot. The first the database ist shutdowned (consistent backup), then the snapshot is created and after it the database opened. How can I use RMAN to daily incremental backup of this oracle database? After creating snapshot is database opened and RMAN must backup it online? Or offline?

I thought to shutdown the database, create snapshot, open database and with RMAN to backup the created snapshot incrementally. Is this possible?

Re: backup oracle non-archive database after snapshot with RMAN

Eric Antunes — Mon, 30 May 2005 09:07:22 GMT

Hi Rischard,

You can only do online backups with the database in archivelog mode (with or without RMAN) so, you have 2 solutions:

1 - In the present database configuration: backup first and startup after the database;

2 - In archivelog configuration: startup the database first and backup after;

Best Regards,

Eric Antunes

Re: backup oracle non-archive database after snapshot with RMAN

Steven E. Protter — Mon, 30 May 2005 09:12:52 GMT

If you have online JFS, you can do a backup according to the following outline.

Bring down the database.
Bring up a special snapshot logical volume to hold all writes to the database, about 20-25% of the size of the database itself.
Bring up the database.

# First three steps take a very short time.

Back up the database using rman or simple OS copy.

Close the special snapshot logical volume, which writes all changes to the original logical volume/filesystem.

This process enables you to get cold backups of oracle databases with actual downtime of less than a minute, depending on factors such as database size and speed of shutdown/startup.

SEP

Re: backup oracle non-archive database after snapshot with RMAN

Richard Kupca — Mon, 30 May 2005 09:33:47 GMT

Eric, thanx for response...

If I understand the RMAN cannot backup incrementally the database which is in non-archive mode?

For offline backups, the database needs to be shut down and restarted in mount mode. The database does not have to be in archivelog mode. BUt what about incremental backup?

Re: backup oracle non-archive database after snapshot with RMAN

Eric Antunes — Mon, 30 May 2005 10:05:41 GMT

Hi again,

"If I understand the RMAN cannot backup incrementally the database which is in non-archive mode?"

No because RMAN cannot backup an open (online) non-archivelog database.

"For offline backups, the database needs to be shut down and restarted in mount mode. The database does not have to be in archivelog mode. BUt what about incremental backup?"

No. For offline backups the sequence is the following:

1 - Shutdown database (I never tried to backup a mounted database so I don't know. Anyway, you can do little with a mounted database...)
2 - copy database files
3 - Startup database

Incremental backups are possible to DLT tapes (with tar)

Best Regards,

Eric Antunes

Re: backup oracle non-archive database after snapshot with RMAN

Devender Khatana — Mon, 30 May 2005 10:20:32 GMT

Hi,

What is the use of you business copy volume of you can not take offline backup with second copy of data?

1.Check synchronization status of both copies. Once it is synced.

2. Shutdown databace.

3. Split copies.

4. Start database with primary copy.

5. Mount secondry copy on same or another host and take backup.

6. After backup resynchronize two copies.

HTH,
Devender

Re: backup oracle non-archive database after snapshot with RMAN

Richard Kupca — Mon, 30 May 2005 10:24:34 GMT

Devender,
we cannot do split mirror (insufficient disk space), only virtual array.

Thanx to all for responses.

Re: backup oracle non-archive database after snapshot with RMAN

Jean-Luc Oudart — Mon, 30 May 2005 11:06:00 GMT

Hi

Firstly, I'd like to say that if these are production databases you should switch archive mode on.

see documentation mentioned in these threads :
http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=363066
http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=877481

Regards
Jean-Luc

Re: backup oracle non-archive database after snapshot with RMAN

Eric Antunes — Mon, 30 May 2005 11:13:09 GMT

I also think you should switch to archivelog since the time to do cold backups would be unaceitable. And RMAN is the right tool to do your incremental backups!!

Best Regards,

Eric Antunes

Re: backup oracle non-archive database after snapshot with RMAN

Yogeeraj_1 — Mon, 30 May 2005 23:14:49 GMT

hi,

Eric is right!

If you don't want to take any risk with your database, Switch to archivelog mode and do only HOT BACKUPs. RMAN is the solution for all you backups and recovery!!

Test it and see how efficient it is!

best regards
yogeeraj

Re: backup oracle non-archive database after snapshot with RMAN

renarios — Tue, 31 May 2005 06:16:55 GMT

Hi Rischard,

Another advantage of rman is: If you create a full backup, it does not take use space of your tablespace allocation (snapshot does!), but only the high-watermark size. This can reduce your backup size a lot!
I recommend you to buy the Oracle Press RMAN backup & recovery book.

Cheerio,

Renarios