Re: [sfpug] DATA directory on network attached storage - Mailing list pgsql-performance

From Aditya
Subject Re: [sfpug] DATA directory on network attached storage
Date
Msg-id 20050411182032.GA48183@mighty.grot.org
Whole thread Raw
In response to Re: [sfpug] DATA directory on network attached storage  (Joe Conway <mail@joeconway.com>)
List pgsql-performance
On Mon, Apr 11, 2005 at 10:59:51AM -0700, Joe Conway wrote:
> >FWIW, if I were to do this anew, I would probably opt for iSCSI over GigE
> >with
> >a NetApp.
>
> Any particular reason? Our NetApp technical rep advised nfs over iSCSI,
> IIRC because of performance.

I would mount the Netapp volume(s) as a block level device on my server using
iSCSI (vs. a file-based device like NFS) so that filesystem parameters could
be more finely tuned and one could really make use of jumbo frames over GigE.

But that level of tuning depends on load after all and with a Netapp you can
have both, so maybe start with having your databases on an NFS volume on the
Netapp, and when you have a better idea of the tuning requirements, move it
over to a iSCSI LUN.

I'm not sure I understand why NFS would perform better than iSCSI -- in any
case, some large Oracle dbs at my current job are moving to iSCSI on Netapp
and in that environment both Oracle and Netapp advise iSCSI (probably because
Oracle uses the block-level device directly), so I suspend the difference in
performance is minimal.

Adi

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