From owner-freebsd-stable@FreeBSD.ORG Tue Feb 8 15:15:42 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 647B7106564A for ; Tue, 8 Feb 2011 15:15:42 +0000 (UTC) (envelope-from hausen@punkt.de) Received: from kagate.punkt.de (kagate.punkt.de [217.29.33.131]) by mx1.freebsd.org (Postfix) with ESMTP id EC4DC8FC18 for ; Tue, 8 Feb 2011 15:15:41 +0000 (UTC) Received: from hugo10.ka.punkt.de ([217.29.45.10]) by gate2.intern.punkt.de with ESMTP id p18FFeIf056828; Tue, 8 Feb 2011 16:15:40 +0100 (CET) Received: from [217.29.45.124] ([217.29.45.124]) by hugo10.ka.punkt.de (8.14.2/8.14.2) with ESMTP id p18FFeiu051751; Tue, 8 Feb 2011 16:15:40 +0100 (CET) (envelope-from hausen@punkt.de) Mime-Version: 1.0 (Apple Message framework v1082) Content-Type: text/plain; charset=iso-8859-1 From: "Patrick M. Hausen" In-Reply-To: Date: Tue, 8 Feb 2011 16:15:35 +0100 Content-Transfer-Encoding: quoted-printable Message-Id: <16407D66-5303-4FF1-85D1-9372B4135C5A@punkt.de> References: <1297026074.23922.8.camel@ubuntu> <20110207045501.GA15568@icarus.home.lan> <1297065041.754.12.camel@ubuntu> <20110207085537.GA20545@icarus.home.lan> <6E948342-DEFF-4DEB-B0DC-990B647549EB@punkt.de> To: Tom Evans X-Mailer: Apple Mail (2.1082) Cc: freebsd-stable Subject: Re: 8.1 amd64 lockup (maybe zfs or disk related) 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: Tue, 08 Feb 2011 15:15:42 -0000 Hello, Am 08.02.2011 um 16:00 schrieb Tom Evans: > My home file server is similar in spec to that - Core 2 Duo, 4 GB RAM > and running 8.2-RC3/amd64, with a pool with two 6 x 1.5 TB raidz > arrays, for a total capacity of ~16 TB. The only ZFS settings I have > changed from default are: >=20 > # Allow prefetch (normally disabled for 4GB or less RAM) > vfs.zfs.prefetch_disable=3D0 > # Don't let ZFS use UMA, restricts available memory > vfs.zfs.zio.use_uma=3D0 >=20 > I think vfs.zfs.zio.use_uma defaults to 0 now anyway. >=20 > I've never had a crash related to memory pressure or any other ZFS > issue - it doesn't get that stressed. YMMV! Yes, it may - and it does ;-) With no tuning at all my FreeNAS (FreeBSD 7.3, amd64, 4 GB RAM, 4 TB = raidz2) crashes within minutes if I copy larger amounts of data via SMB or AFP = to the ZFS.=20 With these settings it's perfectly stable, but I figured from Jeremy's = that they might not be optimal: vm.kmem_size_max=3D"1024M" vm.kmem_size=3D"1024M" vfs.zfs.arc_max=3D"100M" vfs.zfs.prefetch_disable=3D"0" And with the very same settings on our bigger backup box I really need = to improve performance somehow. We are backing up >50 hosts nightly with Amanda. I got from this post that I definitely should increase memory on this machine: = http://constantin.glez.de/blog/2010/06/closer-look-zfs-vdevs-and-performan= ce Kind regards, Patrick --=20 punkt.de GmbH * Kaiserallee 13a * 76133 Karlsruhe Tel. 0721 9109 0 * Fax 0721 9109 100 info@punkt.de http://www.punkt.de Gf: J=FCrgen Egeling AG Mannheim 108285