Re: 10g RAC Install with Raw Devices

From: Alex Gorbachev <gorbyx_at_gmail.com>
Date: Wed, 28 Mar 2007 22:06:39 -0500
Message-ID: <c2213f680703282006t6bc76ea1t1e4a9e081e37bc5b@mail.gmail.com>

Don't use raw devices if you are running Oracle 10.2.0.2 (or 3?) on Linux. * Raw devices are being kind of depreciated in Linux. * Additional level of complexity (bind + permissions) so more likely to fail.

The problem with block devices (/dev/sd*) is that IO to block devices is buffered IO - going via OS cache. Unless you open them with O_DIRECT flag. Starting with 10.1 (IIRC) Oracle adds this to datafile open call (filesystemio_options must be at least directio?). With 10.2.0.1 the same is done for OCR - it's opened with O_DIRECT. However, voting disks open call still have a bug so during installation of 10.2.0.1 you will need to bind voting disks at least. After upgrade to later patchset (I think 10.2.0.2 is enough but don't remember - need to check list of bugs fixed), voting disk is also opened with O_DIRECT.

On 3/28/07, Naqi Mirza <naqimirza_at_yahoo.com> wrote:

> How did you setup the raw devices ? Did you bind raw partitions to your raw
> devices. I'm not an expert on linux but I see you're specifying /dev/sda2 -
> once bound shouldnt this be something like /dev/raw/raw1 ?
> I haven't had the installer complain about devices, but I have had clufvy
> fail on the shared storage check - but that was specific to the hp-ux
> platform.

-- 
Best regards,
Alex Gorbachev

http://www.oracloid.com
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Received on Wed Mar 28 2007 - 22:06:39 CDT