Date: Tue, 8 Feb 2011 16:15:35 +0100 From: "Patrick M. Hausen" <hausen@punkt.de> To: Tom Evans <tevans.uk@googlemail.com> Cc: freebsd-stable <freebsd-stable@freebsd.org> Subject: Re: 8.1 amd64 lockup (maybe zfs or disk related) Message-ID: <16407D66-5303-4FF1-85D1-9372B4135C5A@punkt.de> In-Reply-To: <AANLkTinqVpusdH8gQhvxC8raZUFD08GXgTKiLnAhCtjW@mail.gmail.com> 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> <AANLkTinqVpusdH8gQhvxC8raZUFD08GXgTKiLnAhCtjW@mail.gmail.com>
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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
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