Re: RMAN & SQL Backtrack

From: Ron Rogers <RROGERS_at_galottery.org>
Date: Wed, 16 Jul 2003 13:35:51 -0400
Message-Id: <25937.338098@fatcity.com>

I'll second what Ruth says about backup to disk then use the OS tape routine to archive off of the diaks. I would keep at least 2 disk backups available on disk. It is faster to perform a restore from a disk based backup than from a sequential tape. Restore on datafile from RMAN - 20 min. mount the OS tapes and search for the backed up datafile - all day. Now if I can get the sysadmin to only backup the RMAN files daily rather than a complete disk image each night.
Ron

>>> rgramolini_at_tax.state.vt.us 07/16/03 02:19PM >>>
MessageIf you have to work on the cheap, you can put the backups to tape and then copy them to tape using the OS backup software. It isn't elegant, but it works!

Ruth

Original Message ----- From: Arup Nanda To: Multiple recipients of list ORACLE-L Sent: Wednesday, July 16, 2003 1:24 PM Subject: Re: RMAN & SQL Backtrack

Wow! Heady!!

It's mighty nice of you to include my name in this illustrious list, Mladen; but I don't consider myself to be in the same league :) Better yet, count yourself in there.

Talking about the business at hand - you are absolutely right; one of the "myths" (of the several) is that RMAN is free. It is, as long as you don't put it on tape. Once you bring tape to the picture, you are talking money, sometimes big money (as in Tivoli), sometimes small (as in BrightStor). However, the solution to usedisk could still be relevant and applicable in some cases, especially in small companies.

Besides the Freeman book, I would also suggest another one - Oracle RMAN Pocket Reference by Darl Kuhn and Scott Schulze, ISBN 0-596-00233-5. It predates the Freeman book and I learned my ropes from it. It's a pocket reference; but it's truly one of those things where size belies the content.

Learning curve could be formidable. Remember you need to learn a new "language", and it is arcane. When youventure into territories of tuning the tape buffers, etc, the process could be quite involved. I just finished setting up and tuning a RMAN setup for a 2 TB database using IBM Tivoli Storage Manager agent and the details of the process using the IBM Red Books was nightmarish!

Regards,

Arup Nanda

Original Message ----- From: Gogala, Mladen To: Multiple recipients of list ORACLE-L Sent: Wednesday, July 16, 2003 11:39 AM Subject: RE: RMAN & SQL Backtrack

I don't have any experience with SQL*Backtrack and I do have some experience

with RMAN. Here are my comments:

RMAN is reliable. Once you write the backup scripts, they are executed by operations and there no surprises. In order to rely on those scripts, one needs to test them, especially the recovery part.
RMAN needs a 3rd party backup software to run. Things like OmniBackup, Tivoli, Legato or SyncSort can be rather expensive. RMAN doesn't write to tapes itself. RMAN delegates a backup software contacted through the routines from libobk.so (or libobk.dll or libobk.sl) to do its writing. To get the "libobk.so" from you backup software vendor of choice, you generally have to write a check. That means that RMAN is NOT free.
Before version 9, RMAN was arcane and hard to learn. Thanks to Robert Freeman, it is no longer so. You can learn how to configure and use RMAN and you can find a decent book to learn RMAN from. It's not very hard and it's fairly logical. One reading of the books suffices for a good general understanding.
Quality of the software: RMAN leaves a lot to be desired. Its biggest drawback is the fact that it doesn't do any coordination with the underlying backup catalog. In other words, you can happily declare backup obsolete in RMAN and Legato will not know anything about it and vice versa. You can even delete backup in Legato and reuse the tape while RMAN knows nothing about it. On the other hand, RMAN, in contrast to all other methods, does not put tablespaces into the backup mode, thus generating floods of redo archives. RMAN doesn't backup data blocks that have never been used ("behind the watermark blocks"), which is great if you have a fresh new datafile which was added to the tablespace just in case something might run out of space.
Personnel. Despite the certification process, it is not always easy to find a trained personnel which knows how to use it and how to recover the database. I consider the ability to recover the database a basis for someone to call himself/herself a DBA. You would be surprised how many people which claim that title do not know how to recover the database. Even smaller number knows how to use RMAN.
I would suggest Jared Still, Cary Millsap, Rachel Carmichael, Jonathan Lewis, Wolfgang Breitling, Steve Adams, Gaja V., Arup Nanda, Kirti Deshpande and Anjo Kolk to start the Oracle List certification process. I would trust that one more then the OCP. I apologize to anyone who I might have forgotten.

    Mladen Gogala
    Oracle DBA
    Phone:(203) 459-6855
    Email:mgogala_at_oxhp.com

      -----Original Message-----
      From: Smith, Ron L. [mailto:rlsmith_at_kmg.com] 
      Sent: Wednesday, July 16, 2003 10:59 AM
      To: Multiple recipients of list ORACLE-L
      Subject: RMAN & SQL Backtrack


      We have been using SQL Backtrack for backup and recovery for

about 6 years now. We are being pressured to start using RMAN because it is free. Makes sense but I am wondering about reliability, complexity, learning curve, etc...

Has anyone had experience with both products or anyone new to RMAN that can give me an idea of what to expect?

Thanks!

      Ron
      If you are not the intended recipient of this e-mail message, any

use, distribution or copying of the message is prohibited. Please let me Received on Wed Jul 16 2003 - 12:35:51 CDT