From owner-freebsd-stable@FreeBSD.ORG Sat Jan 1 00:00:31 2011 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id A8DB61065695 for ; Sat, 1 Jan 2011 00:00:31 +0000 (UTC) (envelope-from peterjeremy@acm.org) Received: from mail11.syd.optusnet.com.au (mail11.syd.optusnet.com.au [211.29.132.192]) by mx1.freebsd.org (Postfix) with ESMTP id C17588FC14 for ; Sat, 1 Jan 2011 00:00:23 +0000 (UTC) Received: from server.vk2pj.dyndns.org (c220-239-116-103.belrs4.nsw.optusnet.com.au [220.239.116.103]) by mail11.syd.optusnet.com.au (8.13.1/8.13.1) with ESMTP id p0100KYW022250 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Sat, 1 Jan 2011 11:00:21 +1100 X-Bogosity: Ham, spamicity=0.000000 Received: from server.vk2pj.dyndns.org (localhost.vk2pj.dyndns.org [127.0.0.1]) by server.vk2pj.dyndns.org (8.14.4/8.14.4) with ESMTP id p0100K03043002; Sat, 1 Jan 2011 11:00:20 +1100 (EST) (envelope-from peter@server.vk2pj.dyndns.org) Received: (from peter@localhost) by server.vk2pj.dyndns.org (8.14.4/8.14.4/Submit) id p0100JwN043001; Sat, 1 Jan 2011 11:00:19 +1100 (EST) (envelope-from peter) Date: Sat, 1 Jan 2011 11:00:19 +1100 From: Peter Jeremy To: Adam Stylinski Message-ID: <20110101000019.GC48579@server.vk2pj.dyndns.org> References: <20101230073130.GA55431@zephyr.adamsnet> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="eAbsdosE1cNLO4uF" Content-Disposition: inline In-Reply-To: <20101230073130.GA55431@zephyr.adamsnet> X-PGP-Key: http://members.optusnet.com.au/peterjeremy/pubkey.asc User-Agent: Mutt/1.5.20 (2009-06-14) Cc: freebsd-stable@freebsd.org Subject: Re: slow ZFS on FreeBSD 8.1 X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 01 Jan 2011 00:00:31 -0000 --eAbsdosE1cNLO4uF Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On 2010-Dec-30 02:31:30 -0500, Adam Stylinski wro= te: >I can tell you what the problem is right now, actually. ZFS performs >very poorly on low performance CPUs (i.e. your Atom N330). I would disagree. In this case, the op's most serious problem is a bug in sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c:arc_memory_throttle() which is leading to ARC starvation. The direct effect of this is very poor ZFS I/O performance. It can be identified by very high "inactive" and possibly "cache" memory (as reported by 'systat -v' or top) as well as very high kstat.zfs.misc.arcstats.memory_throttle_count This bug was fixed in r210427 on -current, r211599 on 8.x and r211623 on 7.x. > Try the >same system with a different CPU and you'll get a different result. Not until the above bug is fixed. That said, ZFS is far more CPU intensive than UFS and a more powerful CPU may help - especially if you want gzip compression and/or sha256 checksumming. --=20 Peter Jeremy --eAbsdosE1cNLO4uF Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.15 (FreeBSD) iEYEARECAAYFAk0ebpMACgkQ/opHv/APuIevnACfXrm4QSBnEJADZS2s9QrCFzgd gb0AoIKFyJbGPgepu22cevpIKvz3BG16 =mgI4 -----END PGP SIGNATURE----- --eAbsdosE1cNLO4uF--