From owner-freebsd-fs@FreeBSD.ORG Tue Apr 11 13:41:51 2006 Return-Path: X-Original-To: freebsd-fs@FreeBSD.org Delivered-To: freebsd-fs@FreeBSD.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id D5DD116A402 for ; Tue, 11 Apr 2006 13:41:51 +0000 (UTC) (envelope-from Nicolas.Kowalski@imag.fr) Received: from imag.imag.fr (imag.imag.fr [129.88.30.1]) by mx1.FreeBSD.org (Postfix) with ESMTP id 4A6BE43D48 for ; Tue, 11 Apr 2006 13:41:50 +0000 (GMT) (envelope-from Nicolas.Kowalski@imag.fr) Received: from mail-veri.imag.fr (mail-veri.imag.fr [129.88.43.52]) by imag.imag.fr (8.13.6/8.13.6) with ESMTP id k3BDfk87029016 (version=TLSv1/SSLv3 cipher=AES256-SHA bits=256 verify=NO) for ; Tue, 11 Apr 2006 15:41:46 +0200 (CEST) Received: from corbeau.imag.fr ([129.88.43.162]) by mail-veri.imag.fr with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA:32) (Exim 4.50) id 1FTJ7p-0004oK-Ug for freebsd-fs@FreeBSD.org; Tue, 11 Apr 2006 15:41:45 +0200 Received: from kowalski by corbeau.imag.fr with local (Exim 4.50) id 1FTJ7p-0002oW-Pk for freebsd-fs@FreeBSD.org; Tue, 11 Apr 2006 15:41:45 +0200 To: freebsd-fs@FreeBSD.org References: <20060329152608.GB1375@deviant.kiev.zoral.com.ua> <20060410144904.GC1408@deviant.kiev.zoral.com.ua> <443A7C8E.4020203@centtech.com> <443A8842.6060802@centtech.com> <443A97F9.8090601@centtech.com> <443B8EC1.8080004@centtech.com> From: Nicolas KOWALSKI Date: Tue, 11 Apr 2006 15:41:45 +0200 In-Reply-To: <443B8EC1.8080004@centtech.com> Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: Nicolas Kowalski X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-1.6 (imag.imag.fr [129.88.30.1]); Tue, 11 Apr 2006 15:41:46 +0200 (CEST) X-IMAG-MailScanner-Information: Please contact IMAG DMI for more information X-IMAG-MailScanner: Found to be clean X-MailScanner-From: kowalski@imag.fr Cc: Subject: Re: [patch] giant-less quotas for UFS X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 11 Apr 2006 13:41:52 -0000 Eric Anderson writes: > Nicolas KOWALSKI wrote: >> Eric Anderson writes: >> >>> Nicolas KOWALSKI wrote: >>>> Eric Anderson writes: >>>> >>>>> Nicolas KOWALSKI wrote: >>>>>> Yes, this is exactly what is happening. To add some precision, some >>>>>> students here use calculation applications >>>>>> that allocate a lot of disk space, ususally more than their allowed >>>>>> home quotas; when by error they launch these apps in their home >>>>>> directories, instead of their workstation dedicated space, it makes >>>>>> the server go to its knees on the NFS client side. >>>>> When you say 'to it's knees' - what do you mean exactly? How many >>>>> clients do you have, how much memory is on the server, and how many >>>>> nfsd threads are you using? What kind of load average do you see >>>>> during this (on the server)? >>>> Sorry for the imprecision. >>>> The server is a Dual-Xeon 2.8Ghz, 2GB of RAM, using SCSI3 Ultra320 >>>> 76GB disks and controller. It is accessed by NFS from ~100 Unix >>>> (Linux, Solaris) clients, and by Samba from ~15 Windows XP. The >>>> network connection is GB ethernet. >>>> During slowdowns, it's only from a NFS client view that the server >>>> does not respond. For example, a simple 'ls' in my home directory is >>>> almost immediate, but when it slows down, it can take up to 2 minutes. >>>> On the server, the load average goes to 0.5, compared to a default >>>> maximum of 0.15-0.20. The nfsd processus shows them in the state >>>> "biowr" in top, but nothing is really written, because the quotas >>>> system block any further writes to the user exceeding her/his quotas. >>>> >>> In this case (which is what I suspected), try bumping up your nfsd >>> threads to 128. I set mine very high (I have around 1000 clients), >>> and I can say there aren't really ill-effects besides a bit of memory >>> usage (which you have plenty of). I suspect increasing the threads >>> will neutralize this problem for you. >> Using 128 nfsd threads, I stressed the server, by running on a NFS >> client a small C program, writting continuously in a file, so that the >> user "biguser" (account stored on /export/home2) exceeds his quota. >> It half-works: during the test, users working on another disk >> (/export/home) did not see any difference, but users working on the >> same disk that "biguser" (/export/home2) where almost halted. >> So, this is better, because before everybody was halted, but there is >> still a problem. >> Any other tips ? > > Watch gstat during the testing, and see if the disk that holds the > full partition is really busy. I'm betting it's thrashing the disk > continually checking for free space. I don't think there's any way to > avoid that. Mh, I did not find this "gstat" tool on the system or in the ports; perhaps is it in >= 5.x ? (the server is running 4.11-p15). It is sad I can not do anything about it: such a server pulled down by a single NFS-client. :-( However, Many Thanks for your help and tips. Best regards, -- Nicolas