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RE: raw device

From: Kerber, Andrew W. <>
Date: Thu, 5 Jul 2007 08:47:28 -0500
Message-ID: <>

I agree with you. Any performance you may think you gain by use of raw devices is hard to measure, and offset by the additional administrative problems associated with raw devices. However, I just want to have a better idea of how they need to be set up and managed, at the very least so I can argue the merits with the Unix types.  

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

From: Dan Norris [] Sent: Thursday, July 05, 2007 8:37 AM
To: Kerber, Andrew W.;; ORACLE-L Subject: Re: raw device  

I have yet to find a situation where RAW was that compelling that I'd use it instead of a cooked filesystem. I think that part of the reason you don't find a lot of documentation about it is because not that much exists. IMHO, that's because of supply and demand--that is, there's little demand for such a thing because there isn't much use of RAW devices these days, at least in Oracle environments. RAW devices are more common in Sybase environments from what I've seen.

In short, my advice for managing RAW devices is to use them to create a filesystem on and then mount that :).

Just for curiousity, I searched ML for "raw devices performance" and found some interesting items:
29676.1: Making the decision to use raw devices (an article by Cary Millsap from 1992)
236679.1: Comparing performance between RAW IO vs OCFS vs ext2/3

These are both a little dated, but interesting anyway.


I am also looking for some good device on raw device administration, both in Oracle and and outside of Oracle.  

Having come up on the Oracle developer side of the DBA business, I have been looking for some good documentation on Raw device administration in general. I have used raw devices in the past, but I have always just let the Unix admin hand us the slices, and we set up softlinks to them as we need. I think its time I learned a little more about how to set them up.  

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

[] On Behalf Of Sinardy Xing Sent: Thursday, July 05, 2007 2:54 AM
Subject: raw device  

Hi guys,

Any good link about Oracle + Non RAC + raw device administration?




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Received on Thu Jul 05 2007 - 08:47:28 CDT

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