From owner-freebsd-current@FreeBSD.ORG Wed Nov 2 15:51:39 2005 Return-Path: X-Original-To: current@freebsd.org Delivered-To: freebsd-current@FreeBSD.ORG Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id CF1F416A41F for ; Wed, 2 Nov 2005 15:51:39 +0000 (GMT) (envelope-from anderson@centtech.com) Received: from mh1.centtech.com (moat3.centtech.com [207.200.51.50]) by mx1.FreeBSD.org (Postfix) with ESMTP id 008DF43D73 for ; Wed, 2 Nov 2005 15:51:33 +0000 (GMT) (envelope-from anderson@centtech.com) Received: from [10.177.171.220] (neutrino.centtech.com [10.177.171.220]) by mh1.centtech.com (8.13.1/8.13.1) with ESMTP id jA2FpQau047849; Wed, 2 Nov 2005 09:51:27 -0600 (CST) (envelope-from anderson@centtech.com) Message-ID: <4368E07C.6050003@centtech.com> Date: Wed, 02 Nov 2005 09:51:24 -0600 From: Eric Anderson User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.7.12) Gecko/20051021 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Sven Willenberger References: <1130945793.7893.27.camel@lanshark.dmv.com> In-Reply-To: <1130945793.7893.27.camel@lanshark.dmv.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: ClamAV 0.82/1158/Wed Nov 2 07:29:56 2005 on mh1.centtech.com X-Virus-Status: Clean Cc: current@freebsd.org Subject: Re: Tracking down em problem X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 02 Nov 2005 15:51:39 -0000 Sven Willenberger wrote: > FreeBSD6.0-RC1 (Wed Oct 26 13:31:21 EDT 2005) > > I seem to have an issue with losing connections to an em interface > during process of heavy IO load. There are several variables here so I > am hoping for some guidelines to help troubleshoot this. > > I have a postgresql server (8.0.4) set up on an i386 system. The data > directory is on its own partition (which is actually a gstripe/gmirror > setup -- see the footnote after my problem description). > > I have enabled a replication system from another server. When I started > relication there was a large amount of data that had to be fed to this > server via the em0 interface. During this process, while ssh'ed to the > box, my connection would just hang for a few moments, then it would > recover. However, if I cd to the data directory (stripe/mirror) and > start ls -alrt several times, the connection actually gets broken; not > only my ssh connection but the replication connection from the master > server is broken. > > I have tried to set debug.mpsafenet=0 in /boot/loader.conf to no avail > -- the same issue happens. Preemption is enabled in the kernel, as is > sched_4bsd. I don't really know how to proceed at this point to try and > troubleshoot this issue: as it stands now, it is most definitely a show > stopper for the purposes of this server. I've seen something similar on recent 5.4-STABLE, also using emX devices. I have 3 Dell 1850's showing the same exact issue, and a few 1850's that are not. The ones that are not, are 5.4-RELEASE, and the ones that do, are running 5.4-STABLE. In dmesg, I see a warning like this: Nov 1 19:56:06 hal kernel: em1: Link is up 1000 Mbps Full Duplex I don't see a 'link is down', just 'Link is up'. One machine I've seen this on repeatedly is from about August 16th. I'm using SCHED_4BSD, SMP, and most of the other GENERIC settings. If anyone wants more details, let me know. I have a spare Dell 1850 I can play with. Eric -- ------------------------------------------------------------------------ Eric Anderson Sr. Systems Administrator Centaur Technology Anything that works is better than anything that doesn't. ------------------------------------------------------------------------