Date: Thu, 11 Sep 2008 02:20:47 -0700 From: Jeremy Chadwick <koitsu@FreeBSD.org> To: Michael Grant <mgrant@grant.org> Cc: Kris Kennaway <kris@freebsd.org>, FreeBSD Stable List <freebsd-stable@freebsd.org> Subject: Re: Fresh 7.0 Install: Fatal Trap 12 panic when put under load Message-ID: <20080911092047.GA24499@icarus.home.lan> In-Reply-To: <62b856460809110138o5fb10171h9832ac8b964fa3f6@mail.gmail.com> References: <A6F1ACCEE35A4BC49FC9DFA561ED1131@emea.hubersuhner.net> <62b856460807160743v3fce951eg1b2bd9e50a35ba1d@mail.gmail.com> <BF6724CD748744908D602889CCF119F1@emea.hubersuhner.net> <487E0D1B.2060902@FreeBSD.org> <20080716203900.5jt4qce17gg0og0o@mail.basicnets.co.uk> <A403B8D27BE048E79A94B09C0C520854@emea.hubersuhner.net> <B4E29257-B805-4597-9024-E042F34243D1@mac.com> <62b856460807241309k3cea60dbh24eea677cd6751f7@mail.gmail.com> <4888E207.4020606@FreeBSD.org> <62b856460809110138o5fb10171h9832ac8b964fa3f6@mail.gmail.com>
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On Thu, Sep 11, 2008 at 10:38:36AM +0200, Michael Grant wrote: > My box crashed again: > > panic: kmem_malloc(4096): kmem_map too small: 1073741824 total allocated > cpuid = 0 > Uptime: 33d11h12m58s > Dumping 3327 MB (2 chunks) > chunk 0: 1MB (151 pages) ... ok > chunk 1: 3327MB (851568 pages) <---hung here > > Still no valid dump. > > There is 4gig of physical memory in the machine. > > In /boot/loader.conf, I currently have the following: > > vm.kmem_size=1G > vm.kmem_size_max=1G > vm.kmem_size_scale=2 > > and in my kernel conf file I have: > > options KVA_PAGES=512 > > It stayed up for 33 days this time. Is there anything else I can do? First and foremost: are you using ZFS on this machine? If so, there are many tunables you can apply to try and limit this; I'm willing to bet it's ARC which is doing it. See below. In general, it appears that you need to increase the maximum range of kmem. The kernel attempted to utilise more than 1GB, and your limit is 1G. My machines running RELENG_7 on amd64, with only 2GB of RAM installed, use the following tunables in loader.conf: vm.kmem_size="1536M" vm.kmem_size_max="1536M" If ZFS is in use, I recommend these as well: vfs.zfs.arc_min="16M" vfs.zfs.arc_max="64M" vfs.zfs.prefetch_disable="1" Do not increase kmem_size any larger than 1.5GB; the amount of RAM you have in the machine, with regards to RELENG_7, will not help. This is a known limitation which has been fixed in HEAD/CURRENT (where the limit has been increased to 512GB). See the "Kernel" section below; you'll see the applicable item. http://wiki.freebsd.org/JeremyChadwick/Commonly_reported_issues Your only solution may be to run HEAD/CURRENT. -- | Jeremy Chadwick jdc at parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP: 4BD6C0CB |
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