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RE: Backup and Recovery and DR - RMAN vs. NOT

From: Mark W. Farnham <>
Date: Tue, 2 May 2006 14:35:24 -0400
Message-ID: <>

  1. Since your sys admin has gone to the extra work of backing up tablespace by tablespace to minimize extra redo logging, an argument likely to be persuasive is that RMAN, because it uses the Oracle software rather than OS software to read blocks, cannot get “fractured blocks” and therefore does not need to log complete altered blocks on first change during a given hot backup.
  2. Since your sys admin has put a premium on speed of recovery (which validates your statement that he is very intelligent), just lay down the challenge to see just how fast a recovery he could create using RMAN versus “hot” file backups. This will be a good opportunity to train the junior in executing various recovery scenarios on your test machine.

Good luck and regards,


-----Original Message-----

From: []On Behalf Of Paula Stankus
Sent: Tuesday, May 02, 2006 11:15 AM
To:; Subject: RE:Backup and Recovery and DR - RMAN vs. NOT


My system admin. has a very strong personality and he is very intelligent. However, he also is leaving in about a year and his junior is not at the same level. I just started and they have setup scripts to do alter tablespace to back tablespaces up. In order to decrease their total window they have decided to alter tablespace to begin backup, split mirror, end tablespace backup and resilver. They have bought a large SAN to enable them to do this. I believe Networker Version 7.3 writes out clones at the same time as original tapes. So they will do that as well so that they get their clones for DR faster.

I am definitely used to using RMAN and using Networker solely as the Media Management layer for writing directly to tape. However, I do see the benefits of writing to disk and having some database backups on disk. They also are not interested in purchasing the Oracle agent from networker for the 5 boxes.

I know that they are against Differential backups and RMAN as (a) they think both will complicate the backup process with little payoff and (b) I believe they like controlling thrings through Networker (which of couse could still be done). I am thinking the advantages (especially if a great deal of data is static) with RMAN is:

-easier and more organized tracking of backups (but again, Networker does
this as well)
-ability to do backups at a more granular level with differential backups,
block-level backups and recoveries, read-only tablespace backups solutions available
-ability to write directly to tape and restore/recover directly from tape in
-ability to execute backups/restores/recoveries independently to a larger
extent than having to call the system admin. if we need to go back farther than a day.

I am thinking that RMAN would be a good bet. Does anyone have any good ideas for convincing folks that this is a good option or should I just "go with the flow".


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-- Received on Tue May 02 2006 - 13:35:24 CDT

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