Fileserver panic - FreeBSD 8.1-stable and zfs

Torfinn Ingolfsen torfinn.ingolfsen at
Fri Jun 3 21:18:51 UTC 2011


On Thu, 02 Jun 2011 16:09:21 -0700
Jeremy Chadwick <freebsd at> wrote:

> Anyway, your system has 4GB of RAM installed in it, so on 8.1-STABLE I'd
> recommend you try these settings:
> vm.kmem_size="3584M"
> vm.kmem_size_max="3584M"
> vfs.zfs.arc_max="2048M"
> Now, these are all chosen by me off the top of my head with absolutely
> ZERO knowledge of what the memory usage on this system is like
> **without** ZFS in the picture.  I'm making a lot of assumptions, and
> I'm assuming worst-case scenarios.  For example, if this machine also
> runs mysqld and its tuned to take up a lot of memory, I would advocate
> dropping vfs.zfs.arc_max to 1536M or 1024M.  Please don't drop it "too
> much"; ZFS performs best when it has lots of ARC.
> Since you mentioned going to 8.2-STABLE, all you need to tune on that
> version is one single tunable:
> vfs.zfs.arc_max

The machine now runs 8.2-stable:
root at kg-f2# uname -a
FreeBSD 8.2-STABLE FreeBSD 8.2-STABLE #5: Fri Jun  3 17:20:39 CEST 2011     root at  amd64
And I have added the following to /boot/loader.conf:
Hopefully, this will keep the machine rock solid (unitil something else happens, at least).

Oh, and thanks for your advice - really helpful.

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