From owner-freebsd-fs@FreeBSD.ORG Sun Apr 4 20:41:29 2010 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id AE9B6106566C for ; Sun, 4 Apr 2010 20:41:29 +0000 (UTC) (envelope-from jdc@koitsu.dyndns.org) Received: from qmta08.westchester.pa.mail.comcast.net (qmta08.westchester.pa.mail.comcast.net [76.96.62.80]) by mx1.freebsd.org (Postfix) with ESMTP id 5E7208FC41 for ; Sun, 4 Apr 2010 20:41:29 +0000 (UTC) Received: from omta21.westchester.pa.mail.comcast.net ([76.96.62.72]) by qmta08.westchester.pa.mail.comcast.net with comcast id 1XT81e0041ZXKqc58YhV0J; Sun, 04 Apr 2010 20:41:29 +0000 Received: from koitsu.dyndns.org ([98.248.46.159]) by omta21.westchester.pa.mail.comcast.net with comcast id 1Yl81e0073S48mS3hYl9tp; Sun, 04 Apr 2010 20:45:09 +0000 Received: by icarus.home.lan (Postfix, from userid 1000) id 76A499B419; Sun, 4 Apr 2010 13:41:27 -0700 (PDT) Date: Sun, 4 Apr 2010 13:41:27 -0700 From: Jeremy Chadwick To: Mikle Message-ID: <20100404204127.GA53469@icarus.home.lan> References: <20100404191844.GA5071@takino.homeftp.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100404191844.GA5071@takino.homeftp.org> User-Agent: Mutt/1.5.20 (2009-06-14) Cc: freebsd-fs@freebsd.org Subject: Re: Strange ZFS performance 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: Sun, 04 Apr 2010 20:41:29 -0000 On Sun, Apr 04, 2010 at 11:18:45PM +0400, Mikle wrote: > Hello, list! > I've got some strange problem with one-disk zfs-pool: read/write performance for the files on the fs (dd if=/dev/zero of=/mountpoint/file bs=4M count=100) gives me only 2 MB/s, while reading from the disk (dd if=/dev/disk of=/dev/zero bs=4M count=100) gives me ~70MB/s. > pool is about 80% full; PC with the pool has 2GB of ram (1.5 of which is free); i've done no tuning in loader.conf and sysctl.conf for zfs. In dmesg there is no error-messages related to the disk (dmesg|grep ^ad12); s.m.a.r.t. seems OK. > Some time ago disk was OK, nothing in software/hardware has changed from that day. > Any ideas what could have happen to the disk? Please provide the following output: 1) uname -a 2) sysctl kstat.zfs.misc.arcstats 3) smartctl -a /dev/ad12 Also, does rebooting the box restore write speed (yes, this is a serious question/recommendation)? -- | Jeremy Chadwick jdc@parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP: 4BD6C0CB |