From: mhaverkamp@kcp.com Subject: Re: OT: RAID perf doldrums: advice/recommendations? Date: Fri, 28 Oct 2005 09:25:19 -0500 Message-ID: References: <20051028032149.14201.qmail@web51905.mail.yahoo.com> Mime-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Return-path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.91] helo=mail.sourceforge.net) by sc8-sf-list2.sourceforge.net with esmtp (Exim 4.30) id 1EVVAq-00068D-At for nfs@lists.sourceforge.net; Fri, 28 Oct 2005 07:25:40 -0700 Received: from mailhost2.os.kcp.com ([198.124.201.32]) by mail.sourceforge.net with esmtp (Exim 4.44) id 1EVVAp-0002RE-1M for nfs@lists.sourceforge.net; Fri, 28 Oct 2005 07:25:40 -0700 In-Reply-To: <20051028032149.14201.qmail@web51905.mail.yahoo.com> To: nfs@lists.sourceforge.net 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: If you stay with RAID5, get something with a battery backed write cache. That will make a huge difference in RAID5 performance. Michael Haverkamp nfs-admin@lists.sourceforge.net wrote on 10/27/2005 10:21:49 PM: > Hello, > > Recently we turned on a RAID-backed NFS server that fell flat on its face > as soon as it started to see even moderate activity (particularly IMAP > traffic from Courier-IMAP). Through help on the Courier mailing list, the > problem appears to be very poor throughput to our hard drives (although > systems is not my strong point, so I hope there is not something else I've > overlooked). > > Our choice to go with consumer-grade hardware seems to have bit us hard. > We are using the oft-maligned 3Ware 85xx series RAID5 controller and three > Hitachi Deskstar 7k250 (250GB) SATA drives. The NFS serves up the mailstore > for a system that does about 60 mail messages/min, plus IMAP against the > mailstore (which is what brings the hurt), and some moderately (much more > than Joe Bob's homepage, but not Slashdot) trafficed web content. We were > able to buy some time by moving our (ext3) journal off of the same device, > fiddle with a couple NFS settings (nodiratime,noatime), but it is still > woefully slow. > > Are we completely wrong to give up on this hardware? If anyone is > interested in giving advice in that realm, I am happy to provide more stats > (like the fact that the machine sits at near 100% iowait all day long). > > But instead of sticking it out with that hardware, we are thinking about a > couple possibilities, but a look around Google just found too many "shopping" > sites, and not enough real information and comparisons. We are wanting > advice for proven performers: RAID controller cards and drives. We had been > hoping not to have to pay the hefty costs that SCSI incurrs, but at this > point we are considering the possibility, so advice on both sides of the > fence is sought. > > We are also quite curious about just running with software raid instead, > since there seems to be a growing movement that claims there is no reason it > cannot be as (or more) reliable and fast -- especially compared to the piece > of $@^!% that we apparently got. :) > > Thoguhts and links highly appreciated! > > > > > > > __________________________________ > Yahoo! Mail - PC Magazine Editors' Choice 2005 > http://mail.yahoo.com > > > ------------------------------------------------------- > This SF.Net email is sponsored by the JBoss Inc. > Get Certified Today * Register for a JBoss Training Course > Free Certification Exam for All Training Attendees Through End of 2005 > Visit http://www.jboss.com/services/certification for more information > _______________________________________________ > NFS maillist - NFS@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/nfs ------------------------------------------------------- This SF.Net email is sponsored by the JBoss Inc. Get Certified Today * Register for a JBoss Training Course Free Certification Exam for All Training Attendees Through End of 2005 Visit http://www.jboss.com/services/certification for more information _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs