From mboxrd@z Thu Jan 1 00:00:00 1970 From: thomas62186218@aol.com Subject: Re: Benchmarks: Linux Kernel RAID vs a Hardware RAID setup Date: Tue, 15 Jul 2008 12:50:57 -0400 Message-ID: <8CAB4B2168C7183-B68-AD2@webmail-ng19.sysops.aol.com> References: <1216130769.5633.318.camel@sam.localdomain> <20080715163932.GA23164@rap.rap.dk> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <20080715163932.GA23164@rap.rap.dk> Sender: linux-raid-owner@vger.kernel.org To: keld@dkuug.dk, monkeyiq@users.sourceforge.net Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids Hi Ben, Nice reporting on the benchmarks. It would be helpful though to run=20 these tests without a file system involved, using a block level=20 benchmark utility like fio or similar to really measure the RAID=20 performance in isolation. While you did use a file system in both your=20 hardware and software RAID tests, before directly implicating software=20 RAID, it makes sense to isolate it as much as possible in the testing=20 by eliminating the file system for benchmarks. Thanks again for the report! -Thomas -----Original Message----- =46rom: Keld J=C3=B8rn Simonsen To: Ben Martin Cc: linux-raid@vger.kernel.org Sent: Tue, 15 Jul 2008 9:39 am Subject: Re: Benchmarks: Linux Kernel RAID vs a Hardware RAID setup On Wed, Jul 16, 2008 at 12:06:09AM +1000, Ben Martin wrote: > Hi, > Apologies if posting this here is inappropriate but a recent articl= e > of mine compares the Linux Kernel RAID code to an $800 hardware RAID > card and might be of interest to list members: > > http://www.linux.com/feature/140734 It is (at least to me) very interesting to see comparisons on HW vs SW raid. I think tho, that you give it some bias not testing the best configurations for Linux SW raid. For example raid10, the f2 and o2 layouts are faster than n2, and you don't know if Adaptec has some kind of improved layout. It would be interesting=20 if you could enhance your article with=20 benchmarks on raid10, f2 and o2 layouts. I think they would outperform HW raid, at least on input. And I would like to see how they perform on outout and rewrite, with ext3 and xfs. We do have some tests, but many of them are without a file system layer. I would also welcome test with mobo HW RAID - Many mobo's today come with some HW raid functionality, and many people would be in the situation of whether to choose a HW or SW configuration. best regards keld -- To unsubscribe from this list: send the line "unsubscribe linux-raid" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-raid" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html