From owner-freebsd-questions@FreeBSD.ORG Mon Jan 18 20:34:58 2010 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 52996106568B for ; Mon, 18 Jan 2010 20:34:58 +0000 (UTC) (envelope-from freebsd-questions@pp.dyndns.biz) Received: from proxy1.bredband.net (proxy1.bredband.net [195.54.101.71]) by mx1.freebsd.org (Postfix) with ESMTP id 042F08FC16 for ; Mon, 18 Jan 2010 20:34:57 +0000 (UTC) Received: from ipb1.telenor.se (195.54.127.164) by proxy1.bredband.net (7.3.140.3) id 4AD3E1C00274076B; Mon, 18 Jan 2010 21:34:56 +0100 X-SMTPAUTH-B2: X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AtA4AP5UVEtV4js3PGdsb2JhbACBRoZwk0ABAQEBN7hThDME X-IronPort-AV: E=Sophos;i="4.49,298,1262559600"; d="scan'208";a="27530636" Received: from c-373be255.107-1-64736c10.cust.bredbandsbolaget.se (HELO gatekeeper.pp.dyndns.biz) ([85.226.59.55]) by ipb1.telenor.se with ESMTP; 18 Jan 2010 21:34:56 +0100 Received: from [192.168.69.67] (phobos [192.168.69.67]) by gatekeeper.pp.dyndns.biz (8.14.3/8.14.3) with ESMTP id o0IKYsjG041717; Mon, 18 Jan 2010 21:34:54 +0100 (CET) (envelope-from freebsd-questions@pp.dyndns.biz) Message-ID: <4B54C5EE.5070305@pp.dyndns.biz> Date: Mon, 18 Jan 2010 21:34:54 +0100 From: =?ISO-8859-15?Q?Morgan_Wesstr=F6m?= User-Agent: Thunderbird 2.0.0.23 (X11/20091010) MIME-Version: 1.0 To: "O. Hartmann" References: <4B54C100.9080906@mail.zedat.fu-berlin.de> In-Reply-To: <4B54C100.9080906@mail.zedat.fu-berlin.de> Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Cc: FreeBSD Stable , freebsd-questions@freebsd.org Subject: Re: immense delayed write to file system (ZFS and UFS2), performance issues X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 18 Jan 2010 20:34:58 -0000 O. Hartmann wrote: > I realise a strange behaviour of several FreeBSD 8.0-STABLE/amd64 boxes. > All boxes have the most recent STABLE. One box is a UP system, two > others SMP boxes, one with a Q6600 4-core, another XEON with 2x 4-cores > (Dell Poweredge III). > > Symptome: All boxes have ZFS and UFS2 filesystems. Since two weeks or > so, sometimes the I/O performance drops massively when doing 'svn > update', 'make world' or even 'make kernel'. It doesn't matter what > memory and how many cpu the box has, it get stuck for several seconds > and freezing. On the UP box, this is sometimes for 10 - 20 seconds. > A very interesting phenomenon is the massively delayed file writing on > ZFS filesystems I realise. Editing a file in 'vi' running on one XTerm > and having in another Xterminal my shell for compiling this file, it > takes sometimes up to 20 seconds to get the file updated after it has > been written. It's like having an old, slow NFS connection with long > cache delays. > These massively delayed file transactions are not necessarely under > heavy load, sometimes they occur in a relaxed situation. They seem to > occur much more often on the UP box than on the SMP boxes, but this > strange phenomenon also occur on the Dell Poweredge II, which has 16GB > RAM and summa summarum 16 cores. This phenomenon does occur on ZFS- and > UFS2 filesystems as well. It is hardly reproducable. > > Is there any known issue? > > Ragrds, > Oliver The disks involved don't happen to be Western Digital Green Power disks, do they? The Intelli-Park function in these disks are wrecking havoc with I/O in Linux-land at least, causing massive stalls and iowait through the roof during the 25-30 seconds it takes for the heads to unload after parking. I have two of these disks sitting on my desk now collecting dust... /Morgan