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: > > # Allow prefetch (normally disabled for 4GB or less RAM) > vfs.zfs.prefetch_disable=0 > # Don't let ZFS use UMA, restricts available memory > vfs.zfs.zio.use_uma=0 > > I think vfs.zfs.zio.use_uma defaults to 0 now anyway. > > 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. With these settings it's perfectly stable, but I figured from Jeremy's that they might not be optimal: vm.kmem_size_max="1024M" vm.kmem_size="1024M" vfs.zfs.arc_max="100M" vfs.zfs.prefetch_disable="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-performance Kind regards, Patrick -- punkt.de GmbH * Kaiserallee 13a * 76133 Karlsruhe Tel. 0721 9109 0 * Fax 0721 9109 100 [email protected] http://www.punkt.de Gf: Jürgen Egeling AG Mannheim 108285 _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "[email protected]"
