From owner-freebsd-fs@FreeBSD.ORG Fri Oct 5 13:40:19 2007 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 A55D016A419; Fri, 5 Oct 2007 13:40:19 +0000 (UTC) (envelope-from cb@severious.net) Received: from ion.gank.org (ion.gank.org [69.55.238.164]) by mx1.freebsd.org (Postfix) with ESMTP id 82AE713C44B; Fri, 5 Oct 2007 13:40:19 +0000 (UTC) (envelope-from cb@severious.net) Received: by ion.gank.org (Postfix, from userid 1001) id 3D2DA1109C; Fri, 5 Oct 2007 08:40:19 -0500 (CDT) Date: Fri, 5 Oct 2007 08:40:17 -0500 From: Craig Boston To: Pawel Jakub Dawidek Message-ID: <20071005133958.GA1123@nowhere> Mail-Followup-To: Craig Boston , Pawel Jakub Dawidek , freebsd-fs@FreeBSD.org, freebsd-current@FreeBSD.org References: <20071005000046.GC92272@garage.freebsd.pl> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20071005000046.GC92272@garage.freebsd.pl> User-Agent: Mutt/1.4.2.3i Cc: freebsd-fs@FreeBSD.org, freebsd-current@FreeBSD.org Subject: Re: ZFS kmem_map too small. 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: Fri, 05 Oct 2007 13:40:19 -0000 On Fri, Oct 05, 2007 at 02:00:46AM +0200, Pawel Jakub Dawidek wrote: > If you can still see those panic, please let me know as soon as possible > and try to describe what your workload looks like, how to reproduce it, > etc. I'd really like ZFS to be rock-stable for 7.0 even on i386. Have two of them for you. My amd64 system is offline for an indeterminate amount of time, so I don't know what its status is. #1) The one I can reproduce it on the most reliably is my old fileserver. It only has 512MB RAM, which I know is below the officially supported limit, but it _used_ to work perfectly (even if a bit slow) with the settings tweaked. hw.machine_arch: i386 hw.realmem: 536309760 vm.kmem_size: 306184192 vfs.zfs.arc_max: 167772160 kern.maxvnodes: 25000 About 1.5-2 months ago it was working fine with the autotuned arc_max value -- I don't remember exactly what it was. Once the panics started I've been slowly bumping it down, but no matter how low I set it, it can't seem to survive a buildworld & buildkernel. I don't have the ZIL disabled on this one, as I'm running PostgreSQL on it and prefer fsync() to work. #2) This one panics far less frequently and is more difficult to trigger. My latest ARC size reduction seems to have it almost stable, but with the autotuned value would panic within the day. Besides the kmem_map too small panic, I sometimes get a "could not allocate kthread stack" panic, which MAY be related. Or it may not. hw.machine_arch: i386 hw.realmem: 2145959936 (2GB) vm.kmem_size: 671088640 vfs.zfs.arc_max: 300000000 kern.maxvnodes: 75000 The other odd thing about this one: vm.kvm_size: 1069543424 vm.kvm_free: 0 I don't know if I should be concerned that kvm_free is consistently zero on this system, but it's a bit strange as all the others I work on have >0. Please let me know if there's any information I can provide that would be useful. Craig