mcdouga9 at egr.msu.edu
Mon Nov 5 09:05:21 PST 2007
On Mon, Nov 05, 2007 at 10:24:14AM +0100, Kris Kennaway wrote:
Thomas Sparrevohn wrote:
>> On Sunday 04 November 2007 15:00:50 Kris Kennaway wrote:
>> Oh my god - Overlooked that ;-) - funny that - Its a bit tricky as it not
>> possibly to dump a kernel
>> when the swap is on ZFS - I did a test with all debugging enabled and the
>> did not show up - which makes it somewhat nasty - I check if I can
>> reproduce it with only DDB enabled
You can still hook up a serial console, or at the very least take
photographs of the screen with the relevant DDB information. Or add
another disk and dump on that.
I have some screenshots of ps in ddb from one of several zfs hangs I've had
on one amd64 system:
I didn't post every single screenful since I don't have a microsd reader handy,
and emailing the pictures off my phone is painful. If I missed a screenshot of
one or more particular processes that might have a telling state, let me know.
I also have a gzipped kernel + dump from a forced panic when it was in this
state, if a developer is interested in it please let me know so I can post it
somewhere private since the system is in NIS and likely has tables cached
It is running a kernel from Oct 17. I tried a kernel with WITNESS, INVARIANTS
etc but it did the same hang without any panic. I completed a zpool scrub
this morning with no errors. Lately zfs seems to wedge up every single night
when rsync from remote servers run. This is the only amd64 system I have zfs on,
the other two are i386 and the problems on those systems have only been kmem panics
which so far have been avoidable.
I can help by checking somewhat specific things and running prescribed tests,
but right now I don't have time to tackle this problem on this system and learn
how to debug it entirely on my own starting with nothing more than a DDB guide
from the handbook. Its not that I refuse to; I recognize its difficult to
join remote skill with local hands for something this technical.
Friday I replaced the motherboard/cpu just as a shot in the dark (since the
system had some strange instability in the past) but this didn't help zfs
(not surprised). When zfs was hung saturday morning, I tried to reboot it
but reboot would not even get far enough to stop new ssh connections.
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