From owner-freebsd-stable@FreeBSD.ORG Mon May 3 12:26:59 2010 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 185F2106564A for ; Mon, 3 May 2010 12:26:59 +0000 (UTC) (envelope-from auryn@zirakzigil.org) Received: from mail.zirakzigil.org (mail.zirakzigil.org [82.63.178.63]) by mx1.freebsd.org (Postfix) with ESMTP id AB4EC8FC08 for ; Mon, 3 May 2010 12:26:58 +0000 (UTC) Received: from localhost (unknown [192.168.1.2]) by mail.zirakzigil.org (Postfix) with ESMTP id 428EF964F6; Mon, 3 May 2010 14:26:49 +0200 (CEST) X-Virus-Scanned: amavisd-new at zirakzigil.org Received: from mail.zirakzigil.org ([192.168.1.2]) by localhost (ext.zirakzigil.org [192.168.1.2]) (amavisd-new, port 10024) with ESMTP id 9Xq5M7MjOYjS; Mon, 3 May 2010 14:26:46 +0200 (CEST) Received: from aurynmob2.giulioferro.it (unknown [192.168.1.2]) (Authenticated sender: auryn@zirakzigil.org) by mail.zirakzigil.org (Postfix) with ESMTPA id 38122964E5; Mon, 3 May 2010 14:26:46 +0200 (CEST) Message-ID: <4BDEC106.3040807@zirakzigil.org> Date: Mon, 03 May 2010 14:26:46 +0200 From: Giulio Ferro User-Agent: Mozilla/5.0 (X11; U; FreeBSD amd64; en-US; rv:1.9.1.7) Gecko/20100223 Thunderbird/3.0.1 MIME-Version: 1.0 To: Jeremy Chadwick , freebsd-stable@freebsd.org References: <4BDEA86E.3050109@zirakzigil.org> <20100503110100.GA93137@icarus.home.lan> In-Reply-To: <20100503110100.GA93137@icarus.home.lan> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Subject: Re: Freebsd 8.0 kmem map too small 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: Mon, 03 May 2010 12:26:59 -0000 On 03.05.2010 13:01, Jeremy Chadwick wrote: > On Mon, May 03, 2010 at 12:41:50PM +0200, Giulio Ferro wrote: > >> NFS server amd64 Freebsd 8.0 recent (2 days ago) >> >> This server has been running for several months without problems. >> Beginning last week, however, I'm experiencing panics (about 1 per day) >> with the error in the subject >> >> Current settings: >> >> >> vm.kmem_size_scale: 3 >> vm.kmem_size_max: 329853485875 >> vm.kmem_size_min: 0 >> vm.kmem_size: 2764046336 >> ... >> hw.physmem: 8568225792 >> hw.usermem: 6117404672 >> hw.realmem: 9395240960 >> ... >> vfs.zfs.l2arc_noprefetch: 0 >> vfs.zfs.l2arc_feed_secs_shift: 1 >> vfs.zfs.l2arc_feed_secs: 1 >> vfs.zfs.l2arc_headroom: 128 >> vfs.zfs.l2arc_write_boost: 67108864 >> vfs.zfs.l2arc_write_max: 67108864 >> vfs.zfs.arc_meta_limit: 431882240 >> vfs.zfs.arc_meta_used: 431874720 >> vfs.zfs.arc_min: 215941120 >> vfs.zfs.arc_max: 1727528960 >> >> >> I've set nothing in either /boot/loader.conf or sysctl.conf >> >> >> What should I do? >> > You need to adjust vm.kmem_size to provide more space for the ARC. > > Below are ZFS-relevant entries in our /boot/loader.conf on production > RELENG_8 systems with 8GB of RAM. The reason we set kmem_size to half > our physical system memory is because I didn't want to risk other > processes which use a larger maxdsiz/dfldsiz/maxssiz to potentially > exhaust all memory. > > > # Increase vm.kmem_size to allow for ZFS ARC to utilise more memory. > vm.kmem_size="4096M" > vfs.zfs.arc_max="3584M" > > # Disable ZFS prefetching > # http://southbrain.com/south/2008/04/the-nightmare-comes-slowly-zfs.html > # Increases overall speed of ZFS, but when disk flushing/writes occur, > # system is less responsive (due to extreme disk I/O). > # NOTE: 8.0-RC1 disables this by default on systems<= 4GB RAM anyway > # NOTE: System has 8GB of RAM, so prefetch would be enabled by default. > vfs.zfs.prefetch_disable="1" > > # Decrease ZFS txg timeout value from 30 (default) to 5 seconds. This > # should increase throughput and decrease the "bursty" stalls that > # happen during immense I/O with ZFS. > # http://lists.freebsd.org/pipermail/freebsd-fs/2009-December/007343.html > # http://lists.freebsd.org/pipermail/freebsd-fs/2009-December/007355.html > vfs.zfs.txg.timeout="5" > > > Thanks, I'll try these settings. I'll keep you posted.