zfs, 1 gig of RAM and periodic weekly

[Freddie Cash]

On Mon, Feb 27, 2012 at 11:02 AM, Nenhum_de_Nos
<matheus at 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.
>>
>> This isn't a sensible combination; I wouldn't try to run ZFS on anything less than 4GB...
>
> regardless of the pool size ?
>
> 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.
>
> As its for home use, some p2p software and mostly music listening and sometimes movie streaming.
>
> should 2GB be that bad, that I should drop it and use UFS instead ?
>
> I may run any version of FreeBSD on it, was planning on 9-STABLE or 9.1.

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).

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.

Do not, under any circumstances, enable dedupe on a system with less
than 16 GB of RAM.  :)

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.

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.

-- 
Freddie Cash
fjwcash at gmail.com