Many processes stuck in zfs

Kevin Oberman oberman at
Wed Mar 10 00:18:30 UTC 2010

> Date: Tue, 9 Mar 2010 21:53:55 +1100
> From: Peter Jeremy <peterjeremy at>
> Sender: owner-freebsd-stable at
> On 2010-Mar-09 10:15:53 +0100, Stefan Bethke <stb at> wrote:
> >Over the past couple of months, I've more or less regularly observed machines having more and more processes stuck in the zfs wchan.  The processes never recover from that,
> How long have you waited?
> There seems to be a problem with low free memory handling that causes ZFS
> to turn into cold molasses.  The work-around is to run a program that
> allocates a decent size chunk of memory and then exits.  The original
> suggestion was something like:
> 	perl -e '@x = (0) x 1000000;'
> I've written a short program that allocates and dirties ~100MB and then
> exits and run it from cron.

Sigh! I found it. I build my systems without NIS and I had the stock
nsswitch.conf file. Fixed.

/me banging my head against the desk.

R. Kevin Oberman, Network Engineer
Energy Sciences Network (ESnet)
Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab)
E-mail: oberman at			Phone: +1 510 486-8634
Key fingerprint:059B 2DDF 031C 9BA3 14A4  EADA 927D EBB3 987B 3751

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