kmem_map too small under ZFS
swhetzel at gmail.com
Mon Jan 7 08:02:38 PST 2008
On 1/7/08, Pete French <petefrench at ticketswitch.com> wrote:
> > vm.kmem_size="512M"
> > vm.kmem_size_max="512M"
> I have similar to this in mine...
> which is about 600 meg - the machine has 2 gig of RAM.
> > vfs.zfs.prefetch_disable="1"
> > vfs.zfs.arc_max="150M"
> > kern.maxvnodes="400000"
> now these I havent got - I did see a reference to disabling the intent log,
> which is what I was about to try. I will give your settings a shot too.
> > Most of these settings came from various mailing list postings. It's
> > possible that some don't do anything useful, but I haven't had a zfs
> > related panic since.
> Worth a try - might see if I can find a way tro reliably trigger the
> opanic and then tyrn these bits back on one at a time too.
I use the following settings that were obtained from the
ZFSTuningGuide a while back.
# ZFS Tunning (amd64) - http://wiki.freebsd.org/ZFSTuningGuide
# kern.maxvnodes="400000" - sysctl.conf
# 1073741824 = 1G
# arc_max = 2 * kmem_size / 3
The commented out settings are no longer in the guide, and I haven't
had any problems with just setting vm.kmem_size* on FreeBSD/amd64.
Is your system FreeBSD/amd64 or FreeBSD/i386? If it is FreeBSD/i386
you will need to increase KVA_PAGES as suggested in the guide.
More information about the freebsd-stable