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Re: 10g RAC on AIX

From: Byron Pearce <>
Date: Sun, 22 May 2005 14:33:10 -0500
Message-Id: <1116790389.5584.42.camel@roma>


This is absolutely viable, but with caveats (see below).

The site where I am is running AIX 5.2ML4 on p570E's. We are not using HACMP, but have the cluster up and running with CRS and ASM (

Best advice: the devil is in the details. Make sure you have *everything* planned out up front (especially in regard to how you are slicing and dicing up the disks for ASM).

Also take into account that you will need to make sure that the OCR and voting disks need to be mirrored by the hardware or OS for 10gR1 (there is no option to multiplex them within Oracle for this version).

The other thing you need to be aware of on AIX is that some of the higher-end IBM storage does not work with ASM due to driver issues. In a nutshell, the sdd driver is setup so that 'root' has to open and write to the device initially, and it doesn't matter what you set the ownership or permissions on the device to be. However, if you setup a long running dd command (or something along that line) to the vpath device then the 'oracle' user can write to it for as long as the dd is running, but the moment it stops then the non-'root' user starts getting permission denied errors. Since ASM runs under 'oracle' and needs control of the disks, this means you can't use ASM in this situation.

I know this is problematic on both the IBM Shark line and the SAN Volume Controller. According to what we have been told, nothing above the Open Storage line (the FastT devices) is going to work until the new sdd drivers are released (supposed to be around 3Q/4Q 2005). I don't know what storage you're considering or what the impact is on non-IBM Storage (EMC, HDS, etc.) but that needs to be a major point of investigation for you.

HTH and good luck.

On Sat, 2005-05-21 at 22:19, Mark Brooks wrote:
> We are considering implementing 10g RAC on IBM p5 series running AIX 5.2
> or 5.3. Probable configuration is 3 or 4 nodes. Quick review of the
> documentation suggests we can use ASM and avoid the HACMP components. Is
> this a viable approach? Any problem areas we need to watch? We are just
> in the planning stages so all suggestions are welcome.
> Thanks
> --

Byron Pearce
Tenure Systems, Inc.			Dallas/Fort Worth, TX

"It's hard to be a ninja when you wear a beeper."

Received on Sun May 22 2005 - 15:38:36 CDT

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