From: Dan Stromberg Subject: RE: NFS tuning - high performance throughput. Date: Wed, 15 Jun 2005 13:11:02 -0700 Message-ID: <1118866263.22484.21.camel@seki.nac.uci.edu> References: Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-4X6A4lYESCMYj2BH8JSD" Cc: "'M. Todd Smith'" , nfs@lists.sourceforge.net, strombrg@dcs.nac.uci.edu Return-path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.11] helo=sc8-sf-mx1.sourceforge.net) by sc8-sf-list2.sourceforge.net with esmtp (Exim 4.30) id 1DieE9-0008Iv-Vp for nfs@lists.sourceforge.net; Wed, 15 Jun 2005 13:11:09 -0700 Received: from dcs.nac.uci.edu ([128.200.34.32]) by sc8-sf-mx1.sourceforge.net with esmtp (TLSv1:AES256-SHA:256) (Exim 4.41) id 1DieE7-0002Bs-Es for nfs@lists.sourceforge.net; Wed, 15 Jun 2005 13:11:09 -0700 To: Roger Heflin In-Reply-To: Sender: nfs-admin@lists.sourceforge.net Errors-To: nfs-admin@lists.sourceforge.net List-Unsubscribe: , List-Id: Discussion of NFS under Linux development, interoperability, and testing. List-Post: List-Help: List-Subscribe: , List-Archive: --=-4X6A4lYESCMYj2BH8JSD Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Wed, 2005-06-15 at 14:52 -0500, Roger Heflin wrote: > The mount/remount (unless you time how long it takes to unmount), > will potentially still skew the write test, and the writes > will still be happening for quite a while after the dd completes. Or unless you sync twice? Or write synchronously. :) > Roger=20 >=20 > > -----Original Message----- > > From: Dan Stromberg [mailto:strombrg@dcs.nac.uci.edu]=20 > > Sent: Wednesday, June 15, 2005 2:14 PM > > To: Roger Heflin > > Cc: 'M. Todd Smith'; nfs@lists.sourceforge.net;=20 > > strombrg@dcs.nac.uci.edu > > Subject: RE: [NFS] NFS tuning - high performance throughput. > >=20 > >=20 > > A bigger dd test should work - if you use about 3x your=20 > > physical memory, you'll probably be fine doing it that way. > >=20 > > Another way that may work better in -some- cases, is to=20 > > umount the filesystem and re-mount it - except for warm=20 > > restartable filesystems. > >=20 > > On Wed, 2005-06-15 at 10:28 -0500, Roger Heflin wrote: > > > Make the dd test bigger, with 2x the memory size, 50% will be from=20 > > > cache and almost instanteous, with 4x the memory size, 25% will be=20 > > > from cache, bigger runs will get closer to actual reality, on the=20 > > > tests I do I run things 8x, but if you run 2x, 4x, 8x memory you=20 > > > should get a decent graph to give you an idea of what the=20 > > actual value=20 > > > is. > > >=20 > > > Roger > > > Atipa Technologies.=20 > > >=20 > > > > -----Original Message----- > > > > From: nfs-admin@lists.sourceforge.net=20 > > > > [mailto:nfs-admin@lists.sourceforge.net] On Behalf Of M.=20 > > Todd Smith > > > > Sent: Wednesday, June 15, 2005 9:47 AM > > > > To: nfs@lists.sourceforge.net > > > > Subject: Re: [NFS] NFS tuning - high performance throughput. > > > >=20 > > > > Roger Heflin wrote: > > > >=20 > > > > >Are you using the same dd test on the local machine test? =20 > > > > If so cache > > > > >will be a major factor. > > > > > > > > > >Also, raid5 stripe size, bigger is almost always better,=20 > > I would do=20 > > > > >some testing with different strip sizes and see how it=20 > > affects the=20 > > > > >speed, I have never seen less than 32k be faster than 32k. > > > > > > > > > >Are you using md for the raid5 setup or something else=20 > > that has not=20 > > > > >been mentioned? > > > > > > > > > > Roger > > > > > =20 > > > > > > > > > Roger, > > > >=20 > > > > I was told by a consultant we hired to help us with this that 5Gb=20 > > > > test files should be large enough to blow out the caches. > > > > Looking back I realize that must have been when we only=20 > > had 2Gb RAM=20 > > > > in the machine .. > > > > is there a better test I can use to check local rw=20 > > performance, as=20 > > > > well is there a formula or recommended way to calculate how big a=20 > > > > file you should rw to properly check local rw? > > > >=20 > > > > I'll have to ask our soft eng who worked with the=20 > > consultant as to=20 > > > > why that particular stripe size was used. I believe we are using=20 > > > > md, we attempted to use LVM but ran into some problems=20 > > and had some=20 > > > > file inconsistencies that were unacceptable so had to back out of=20 > > > > it. > > > >=20 > > > > Cheers > > > > Todd > > > >=20 > > > > -- > > > > Systems Administrator > > > > ---------------------------------- > > > > Soho VFX - Visual Effects Studio > > > > 99 Atlantic Avenue, Suite 303 > > > > Toronto, Ontario, M6K 3J8 > > > > (416) 516-7863 > > > > http://www.sohovfx.com > > > > ---------------------------------- > > > >=20 > > > >=20 > > > > =20 > > > >=20 > > > >=20 > > > >=20 > > > > ------------------------------------------------------- > > > > SF.Net email is sponsored by: Discover Easy Linux Migration=20 > > > > Strategies from IBM. Find simple to follow Roadmaps,=20 > > straightforward=20 > > > > articles, informative Webcasts and more! Get everything=20 > > you need to=20 > > > > get up to speed, fast. > > > > http://ads.osdn.com/?ad_id=3D7477&alloc_id=3D16492&op=3Dclick > > > > _______________________________________________ > > > > NFS maillist - NFS@lists.sourceforge.net=20 > > > > https://lists.sourceforge.net/lists/listinfo/nfs > > > >=20 > > >=20 > > >=20 > > >=20 > > > ------------------------------------------------------- > > > SF.Net email is sponsored by: Discover Easy Linux Migration=20 > > Strategies=20 > > > from IBM. Find simple to follow Roadmaps, straightforward articles,=20 > > > informative Webcasts and more! Get everything you need to get up to=20 > > > speed, fast. http://ads.osdn.com/?ad_id=3D7477&alloc_id=3D16492&op=3D= click > > > _______________________________________________ > > > NFS maillist - NFS@lists.sourceforge.net=20 > > > https://lists.sourceforge.net/lists/listinfo/nfs > > >=20 > >=20 >=20 --=-4X6A4lYESCMYj2BH8JSD Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (GNU/Linux) iD8DBQBCsItWo0feVm00f/8RAoTxAJwNCboKc/DIkawBMtDn/j9Oj6sTkQCgkEGJ RtQEmAkwrY1UiKVes6S5XhA= =dNKz -----END PGP SIGNATURE----- --=-4X6A4lYESCMYj2BH8JSD-- ------------------------------------------------------- SF.Net email is sponsored by: Discover Easy Linux Migration Strategies from IBM. Find simple to follow Roadmaps, straightforward articles, informative Webcasts and more! Get everything you need to get up to speed, fast. http://ads.osdn.com/?ad_id=7477&alloc_id=16492&op=click _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs