Re: Using NetApp Filers for a DWH

From: Binley Lim <Binley.Lim_at_xtra.co.nz>
Date: Fri, 6 Aug 2004 01:41:21 +1200
Message-ID: <00a401c47af1$e570d2e0$d94e36d2@csnqusvf>

I agree that it's not a RAID-4 problem (or even WAFL), because the OP said this particular problem did _not_ reproduce on 9.2.0.4.

Cannot be a 10g-specific problem either, or you would know...

So it could be an Oracle/NetApp combination (and assuming NFS) problem? ... or the OP missed something?

Original Message ----- From: "Matthew Zito" <mzito_at_gridapp.com> To: <oracle-l_at_freelists.org> Sent: Thursday, August 05, 2004 6:00 PM Subject: Re: Using NetApp Filers for a DWH

>
> That's not it. The RAID-4 has nothing to do with this behavior. The=20
> behavior described is symptomatic of a WAFL filesystem with an=20
> oversubscribed cache. Since WAFL will never overwrite an existing=20
> block, but simply append writes to the next available slot in the free=20=
>
> block list, the tablespace described will effectively be located=20
> half-and-half on two different filesystem regions.
>
> If there was enough (read: a lot) of cache in the filer, this problem=20
> would be mitigated, since all of the recently modified blocks would be=20=
>
> in cache, but overall this is definitely the worst-case situation for
a=20=
>
> Netapp.
>
> Thanks,
> Matt
>
>
> --
> Matthew Zito
> GridApp Systems
> Email: mzito_at_gridapp.com
> Cell: 646-220-3551
> Phone: 212-358-8211 x 359
> http://www.gridapp.com
>
>
> On Aug 4, 2004, at 7:54 PM, Mogens N=F8rgaard wrote:
>
> > I like the NetApp guys, etc. But it is really RAID-4 (no kidding), so
> > perhaps that might explain one or two things? Just guessing...
> >
> > Mogens

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Received on Thu Aug 05 2004 - 08:36:46 CDT