RE: RMAN backups

From: Lex de Haan <lex.de.haan_at_naturaljoin.nl>
Date: Tue, 21 Jun 2005 21:19:49 +0200
Message-Id: <20050621191952.279818010FBA@smtp-out3.tiscali.nl>

incremental RMAN backups can be made *much* faster in 10g if you implement the block change tracking feature.
when implemented, RMAN precisely knows which blocks must be backed up, without the need to inspect all headers.

kind regards,

Lex.

Steve Adams Seminar http://www.naturaljoin.nl/events/seminars.html

-----Original Message-----
From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Ron Rogers
Sent: Tuesday, June 21, 2005 19:27
To: jrsmiley_at_gmail.com; richard.ignizio_at_paetec.com; rgramolini_at_tax.state.vt.us Cc: oracle-l_at_freelists.org
Subject: RE: RMAN backups

Ruth,
You are correct. a level 0 backup for me takes 14 min at 10.4 Gig disk used and the level1 backups takes 14 min at 3.7 Gig. Ron

>>> "Ruth Gramolini" <rgramolini_at_tax.state.vt.us> 06/21/05 1:05 PM >>>
John,

Unless something has changed with 10g, and incremental backup doesn't actually save much time. Rman still has to read the block headers to see if the block needs to be backed up. It mostly saves space on disc if backing up to disk.

Correct me if I am wrong!
Ruth
-----Original Message-----
From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org]On Behalf Of John Smiley
Sent: Saturday, June 18, 2005 11:19 AM
To: richard.ignizio_at_paetec.com
Cc: oracle-l_at_freelists.org
Subject: Re: RMAN backups

Backup times with RMAN are going to vary greatly depending upon the hardware and how many blocks need to be backed up. Even a very large database can be backed up incrementally if very few blocks have changed since the last backup with RMAN. What might be a better yardstick is backup rate. The fastest RMAN backup rate I've seen was published by Amazon a few years back. They attained 2TB / hour.

John Smiley
Technical Management Consultant
TUSC, Inc.

-- http://www.freelists.org/webpage/oracle-l

Received on Tue Jun 21 2005 - 15:25:27 CDT