From: "Matt Heaton" Subject: Re: nfs performance problem Date: Thu, 7 Nov 2002 08:49:09 -0700 Sender: nfs-admin@lists.sourceforge.net Message-ID: <08da01c28675$367ea400$6601a8c0@c1886657a> References: Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Return-path: Received: from rwcrmhc52.attbi.com ([216.148.227.88]) by usw-sf-list1.sourceforge.net with esmtp (Exim 3.31-VA-mm2 #1 (Debian)) id 189ouG-0004K9-00 for ; Thu, 07 Nov 2002 07:49:20 -0800 To: "Baker, Byran" , Errors-To: nfs-admin@lists.sourceforge.net List-Help: List-Post: List-Subscribe: , List-Id: Discussion of NFS under Linux development, interoperability, and testing. List-Unsubscribe: , List-Archive: I didn't understand? What is a good indication of poor seek time? The high number for TPS? I thought a high number meant the drive was handling a huge amount of transactions per second, and not necessarily slow. I would LOVE to have my NFS servers push out 500 TPS on iostat. I have 10 webservers that each ask for between 10-25 files per second from our 3ware 7850 controllers. We get about 200 TPS on the NFS server. Much more and the clients become VERY SLUGGISH, and I get blocked R processes in vmstat on the client. Sometimes 20-40 blocked R processes in vmstat. As soon as I offload some of files from a busy NFS server to another NFS server then the clients settle down and everything works great again, but I only get 1-1.5MB out of each NFS server before this happens! I can get really high TPS out of the server LOCALLY when I do copies etc, its just over NFS with a huge amount of really small files that everything stinks. L8r... Matt > We have a couple of NFS servers with 3ware cards. One is a 3ware 7850 (8 > Maxtor 160GB - 5400RPM) and one is a 3ware 7500-12, both configured with > RAID 5 + Hot Spare. I have all the latest NFS patches applied. If I access > an NFS mounted directory on one of these systems and copy a bunch of little > files (1-2KB), I get 150-250 tps. If I access larger files (90% > 1MB each) > I will normally see 25-60MB/s transfer with 500-700 tps, with peaks of over > 1000 tps - A good indication that disk seek is to blame for the problem with > the small files. > > Thanks, > -Byran > > From: "Matt Heaton" > To: "poczta.dotcom.pl" , > > Subject: Re: [NFS] nfs performance problem > Date: Tue, 5 Nov 2002 13:22:25 -0700 > > I have 3ware cards as well (2 7500 Series 8 drive), just like yours. ALso > with 120 GIG drives (7200) > RPM. Whever I get 150-200 tps in iostat then my NFS runs SO SLOW. I also > only get 1 MB, to 1.5 MB > over NFS. The local speed seems to be ok, not great though. MY OPINION is > that this is because of seek time on the raid > array. I am serving very small files, just like you are. I am requesting > about 200-300 files per second from > each NFS server. So even though our throughput of only 1.5 MB isn't high. > The number of files per second is > actually quite high, and causes things to slow down because of seek time > issues. PLEASE GIVE US CACHEFS SOMEONE?? > > Does anyone have experience with IDE Raid arrays that get over 250 tps in > iostat that work fine? I would > be VERY VERY VERY interested to find out. > > L8r... > > Matt > > > ------------------------------------------------------- > This sf.net email is sponsored by: See the NEW Palm > Tungsten T handheld. Power & Color in a compact size! > http://ads.sourceforge.net/cgi-bin/redirect.pl?palm0001en > _______________________________________________ > NFS maillist - NFS@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/nfs > > ------------------------------------------------------- This sf.net email is sponsored by: See the NEW Palm Tungsten T handheld. Power & Color in a compact size! http://ads.sourceforge.net/cgi-bin/redirect.pl?palm0001en _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs