From: Chip Salzenberg Subject: Debian Bug#235886: nfs-kernel-server inducing load of 8-9 with no good reason for Linux 2.6 clients Date: Thu, 18 Mar 2004 16:09:43 -0500 Sender: nfs-admin@lists.sourceforge.net Message-ID: <20040318210943.GK3605@perlsupport.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: nfs@lists.sourceforge.net Return-path: Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.12] helo=sc8-sf-mx2.sourceforge.net) by sc8-sf-list2.sourceforge.net with esmtp (Exim 4.30) id 1B44mD-0006kF-Nh for nfs@lists.sourceforge.net; Thu, 18 Mar 2004 13:10:05 -0800 Received: from topaz.cx ([66.220.6.227] helo=mail.topaz.cx ident=mail) by sc8-sf-mx2.sourceforge.net with esmtp (TLSv1:DES-CBC3-SHA:168) (Exim 4.30) id 1B44mC-0003pl-99 for nfs@lists.sourceforge.net; Thu, 18 Mar 2004 13:10:04 -0800 To: Neil Brown 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: Neil (or someone), what should I tell this user? ----- Forwarded message from "Steinar H. Gunderson" ----- Subject: Bug#235886: nfs-kernel-server inducing load of 8-9 with no good reason for Linux 2.6 clients From: "Steinar H. Gunderson" To: Debian Bug Tracking System Date: Wed, 03 Mar 2004 00:41:21 +0100 X-Mailer: reportbug 1.50 Package: nfs-kernel-server Version: 1:1.0-2woody1 Severity: important It appears that from time to time, our NFS servers (both 2.4 and 2.6 servers, but both running woody) seem to go into giant loads with almost no traffic (ie. 20-30 connections, but almost no file activity, as confirmed by tcpdump). This is typically in the 7-8-9 range, and the clients in question seem to hang almost indefinitely (like 20 minutes for a simple ls). However, top shows no processes wanting CPU time, so it almost looks like some kind of I/O starvation problem. In addition, we seem to get strange errors like: 00:16:32.330039 129.241.93.186 > 129.241.93.30: icmp: ip reassembly time exceeded [tos 0xc0] (.30 is the NFS server, .186 is one of the NFS clients) Something is clearly wrong here; stopping nfs-kernel-server makes the load drop to zero almost immediately, and substituting nfs-user-server for nfs-kernel-server also fixes the problem. The servers in question are also NFS clients, but there are no stale mounts and we aren't using NFS re-export. These problems seem to coincide with the rollout of Linux 2.6.x (seen the problem with both 2.6.1 and 2.6.3) on the clients, so it seems plausible that something in the Linux 2.6 client is triggering the NFS kernel server code. I'm a bit unsure if I should file this on nfs-kernel-server or on a kernel package; feel free to reassign as needed. -- System Information Debian Release: 3.0 Architecture: i386 Kernel: Linux cassarossa 2.4.25 #1 SMP Wed Feb 18 22:46:21 CET 2004 i686 Locale: LANG=en_US, LC_CTYPE=en_US.ISO8859-1 Versions of packages nfs-kernel-server depends on: ii debconf 1.2.35 Debian configuration management sy ii libc6 2.2.5-11.5 GNU C Library: Shared libraries an ii libwrap0 7.6-9 Wietse Venema's TCP wrappers libra ii nfs-common 1:1.0-2woody1 NFS support files common to client ----- End forwarded message ----- -- Chip Salzenberg - a.k.a. - "I wanted to play hopscotch with the impenetrable mystery of existence, but he stepped in a wormhole and had to go in early." // MST3K ------------------------------------------------------- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs