From: "Jake Hammer" Subject: NFS read ok, write ok, simultaneous R+W=TERRIBLE Date: Wed, 4 Dec 2002 18:44:24 -0800 Sender: nfs-admin@lists.sourceforge.net Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Return-path: Received: from cynaptic.com ([128.121.116.181]) by sc8-sf-list1.sourceforge.net with esmtp (Exim 3.31-VA-mm2 #1 (Debian)) id 18Jm0B-0005Qy-00 for ; Wed, 04 Dec 2002 18:44:35 -0800 Received: from phasmida (dsl081-053-223.sfo1.dsl.speakeasy.net [64.81.53.223]) by cynaptic.com (8.11.6) id gB52iUd13269 for ; Wed, 4 Dec 2002 19:44:30 -0700 (MST) To: "NFS" 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: Hi All, I'm working with a 2.4.19 + all Neil Brown 2.4.19 patches on a P4 Xeon system, 2048MB ram, uniprocessor kernel. Distro is Debian Woody Stable. Disk subsystem is ATA RAID 5, 14 spindles. On writes from 15 100base-T clients via a Foundry switch, I am able to see 45MB/sec writes and 60MB/sec reads. Clients are DD'ing 10GB files to and from the box simultaneously. Mount = mount -o proto=udp,vers=2,wsize=32768,rsize=32768 bigbox:/space The problem is on read + write. As soon as the clients switch from read only or write only and do BOTH read and write, the CPU pegs and performance drops to 3MB/sec (three MB/s)! TOP shows that 4 of the NFSd's are consuming all of the CPU. It's like they are contending for some kind of resource like a lock or something. Any help would be sincerely appreciated. This is very strange behavior. It also happens with 2.4.18 + all Neil Brown patches for 2.4.18. Thanks, Jake Hammer ------------------------------------------------------- This SF.net email is sponsored by: Microsoft Visual Studio.NET comprehensive development tool, built to increase your productivity. Try a free online hosted session at: http://ads.sourceforge.net/cgi-bin/redirect.pl?micr0003en _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs