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Re: OPS and raw filesystems

From: Garry Robbins <Garry.Robbins_at_Labatt.com>
Date: 1997/03/19
Message-ID: <332FEE99.17D2@Labatt.com>#1/1

Colin Polykett wrote:
> > Garry Robbins wrote:
> > They are a requirement for SUN PDB clusters running OPS.
> >
> > Not only the data files, but control files and redo logs
> > must also be raw devices.
> >
>
> Are you sure that redo logs have to be raw devices ?
>
> Datafiles and control files are shared between instances, but redo logs
> are not. There should be no reason why redo logs have to be on raw
> devices.
>
> It may be better for performance but thats a different issue.
>
> ------------------------------------------------------------
> These views are mine, all mine
>
> Colin Polykett polyketc_at_bibip1.wgw.bt.co.uk
> Open Systems ORACLE DBA

From my class notes, "Media recovery uses (archived) redo log files from all threads".

I take this to mean that should a disk device fail, the recovering instance will need access to all threads' redo logs.

Therefore, it would need shared access to redo log files. In the SUN PDB case, that means a raw device for all instances to have access.

From the Oracle7 Parallel Server Concepts and Admin guide, page 5-7 "Log files ... Although the redo log files are independent per instance, each of the log files must still be accessible by all the instances so that recovery is provided for."

However, in our environment we will be temporarily storing our archived log files in a file system on each node.

Since we can't share file systems across PDB cluster nodes (yet) we would have to make the failed thread's archives available to the recovering node (FTP them, import the file system, etc.)

We've double checked our material here, since this is new to us. I think this is correct, but as always, I'm willing to discuss. I'd rather find out basic configuration problems before we get into production...

-- 
Garry D. Robbins             |mailto:Garry.Robbins_at_Labatt.Com |Opinions
Senior Tech. Supp. Specialist|WWW:   http://www.labatt.com/   |expressed
Labatt Breweries of Canada   |Phone: (519) 667-7131           |are mine
London, Ont. CANADA N6A 4M3  |FAX:   (519) 667-7394           |alone.
Received on Wed Mar 19 1997 - 00:00:00 CST

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