Date: Mon, 27 Feb 2012 18:40:43 -0500 From: Charles Sprickman <spork@bway.net> To: Freddie Cash <fjwcash@gmail.com> Cc: "freebsd-stable@freebsd.org" <freebsd-stable@freebsd.org>, Nenhum_de_Nos <matheus@eternamente.info> Subject: Re: zfs, 1 gig of RAM and periodic weekly Message-ID: <E08D43B1-1492-470B-A098-CC32D396F436@bway.net> In-Reply-To: <CAOjFWZ7m8brSZtvyOrRq-QFZKNONdH9m-HE=dEFQvFp=ffWOeg@mail.gmail.com> References: <4F4B0F83.4090600@norma.perm.ru> <B1D93647-EDA3-49EF-85F4-4FF2AA5A893D@mac.com> <977febd5710ecac8cd9ea374ca0193f4.squirrel@109.169.62.232> <CAOjFWZ7m8brSZtvyOrRq-QFZKNONdH9m-HE=dEFQvFp=ffWOeg@mail.gmail.com>
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On Feb 27, 2012, at 5:48 PM, Freddie Cash wrote: > On Mon, Feb 27, 2012 at 11:02 AM, Nenhum_de_Nos > <matheus@eternamente.info> wrote: >> On Mon, February 27, 2012 15:33, Chuck Swiger wrote: >>> On Feb 26, 2012, at 9:07 PM, Eugene M. Zheganin wrote: >>> [ ... ] >>>> all with zfs and one gig of RAM. >>>=20 >>> This isn't a sensible combination; I wouldn't try to run ZFS on = anything less than 4GB... >>=20 >> regardless of the pool size ? >>=20 >> I was planning on making an atom board a file server for my home, and = I have two options: soekris >> net6501 2GB RAM and intel board powered by the 330 atom (says 2GB = limited as well). My plans are >> to use from 4 up to 8 disks, and they should be 2TB at least. >>=20 >> As its for home use, some p2p software and mostly music listening and = sometimes movie streaming. >>=20 >> should 2GB be that bad, that I should drop it and use UFS instead ? >>=20 >> I may run any version of FreeBSD on it, was planning on 9-STABLE or = 9.1. >=20 > You can get away with 2 GB of RAM, if you spend a lot of time manually > tuning things to prevent kmem exhaustion and prevent ZFS ARC from > starving the rest of the system (especially on the network side of > things). >=20 > Definitely go with a 64-bit install. Even with less than 4 GB of RAM, > you'll benefit from the large kmem size and better auto-tuning. >=20 > Do not, under any circumstances, enable dedupe on a system with less > than 16 GB of RAM. :) >=20 > If at all possible, find a motherboard that will let you use more RAM. > 2 GB is usable. But 4 GB is the sweet spot for a simple file server. > And 16 GB is best for a system with over 10 TB of storage in the > pool. >=20 > My home media server is a 32-bit install of FreeBSD 8-STABLE (Dec 2011 > vintage) with only 2 GB of RAM, using 4x 500 GB SATA drives in 2 > mirror vdevs (boot off USB stick). Every couple of weeks it'll lock > up, usually under heavy torrent load. Prior to doing a bunch of "tune > loader.conf; reboot; crash; repeat" cycles, the box was very unstable. > 2 GB is barely enough for ZFS + NFS + Samba + torrents + whatever. Sounds very familiar. Substitute afp for samba and torrents for sabnzbd furiously unpacking things and we're probably doing much the same. 3 = 1TB Samsungs (+1 spare), 2 gmirror'd CF cards for boot. [spork@media ~]$ uptime 6:41PM up 60 days, 8:36, 1 user, load averages: 0.00, 0.02, 0.00 [spork@media ~]$ zpool list NAME SIZE USED AVAIL CAP HEALTH ALTROOT tank1 2.72T 1.89T 850G 69% ONLINE - [spork@media ~]$ grep avail /var/run/dmesg.boot=20 avail memory =3D 2087931904 (1991 MB) [spork@media ~]$ uname -a FreeBSD media..com 8.2-RELEASE FreeBSD 8.2-RELEASE #1: Tue Feb 22 = 04:44:55 EST 2011 spork@media..com:/usr/obj/usr/src/sys/MEDIA i386 Just in case I've hit on some special sauce in the loader.conf, here you go: [spork@media ~]$ cat /boot/loader.conf=20 zfs_load=3D"YES" #vfs.root.mountfrom=3D"zfs:zroot" vm.kmem_size_max=3D"1000M" vm.kmem_size=3D"1000M" vfs.zfs.arc_max=3D"200M" I used to be able to panic it regularly, but I just kept stepping the=20 kmem up and the arc down until it behaved. The uptime would be longer if my power wasn't as flakey. Charles >=20 > --=20 > Freddie Cash > fjwcash@gmail.com > _______________________________________________ > freebsd-stable@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-stable > To unsubscribe, send any mail to = "freebsd-stable-unsubscribe@freebsd.org"
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