zfs, 1 gig of RAM and periodic weekly

Peter Maloney peter.maloney at brockmann-consult.de
Mon Feb 27 07:40:35 UTC 2012

On 02/27/2012 06:07 AM, Eugene M. Zheganin wrote:
> Hi.
> I'm haunted by a weird bug.
> Some of my servers (IBM x3250) hang periodically. And this is always
> saturday morning. Different servers in different cities, all with zfs
> and one gig of RAM. And yeah, it's periodic weekly. I can say more -
> it's  repeatable. 25 minutes ago I typed 'periodic weekly', and 5
> minutes ago I lost this machine from the network (even stopped
> answering to ICMP). This can be solved by any of two methods - either
> increase RAM, or turning off periodic weekly.
> loader.conf (doesn't help):
> zfs_load="YES"
> vfs.root.mountfrom="zfs:zfsroot"
> ng_iface_load="YES"
> ng_ether_load="YES"
> vm.kmem_size="330M"
> vm.kmem_size_max="330M"
> vfs.zfs.arc_max="30M"
> This is 8.2-RELEASE/amd64.
8.2-RELEASE is highly unstable with ZFS in my opinion. For example, my
system with 48 GB of RAM would hang or crash for no apparent reason in
random intervals. Upgrading in September fixed most of it, except 1
random hang possibly related to NFS, and a hang when renaming snapshots
with zvols [new problem after 8.2-RELEASE, PR 161968]. The renaming
snapshot with zvols hang seems fixed since update again in February.

Still unresolved though is that restarting nfsd makes nfsd hang until
reboot. I don't know if 8.2-RELEASE had that problem.

You should consider an update with csup. Make sure you test and monitor
after the upgrade, in case some other funny issues come up, like my
restarting nfsd issue. But of course I chose that over random hangs and

And one word of advice: If you want to upgrade your pools to v28, I
think you should consider recreating your pools as v28 rather than
upgrading. There are some side effects to upgrading, such as logs that
can't be removed.
> The most important question - what to report and how to report this ?
> Thanks.
> Eugene.
> _______________________________________________
> freebsd-stable at freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-stable
> To unsubscribe, send any mail to "freebsd-stable-unsubscribe at freebsd.org"


Peter Maloney
Brockmann Consult
Max-Planck-Str. 2
21502 Geesthacht
Tel: +49 4152 889 300
Fax: +49 4152 889 333
E-mail: peter.maloney at brockmann-consult.de
Internet: http://www.brockmann-consult.de

More information about the freebsd-stable mailing list