FreeBSD unstable on Dell 1750 using SMP?
dan at syz.com
Tue Nov 29 10:58:35 GMT 2005
Thanks everyone for replies made over the past few days about the
"unsolicited" rebooting problem. At first, I thought there was a
memory allocation bug as judged by the output of "netstat -m", but
apparently it's just a cosmetic statistics reporting bug and nothing
related to the instability itself.
Unfortunately, it means that I still haven't been able to find a
solution to the problem (and apparently, I'm not the only one to
experience it). Considering that we only have the one machine, which
happens to be a production machine, that experiences the problem
(infrequently at that), it's difficult to test and resolve. It's
been suggested that FreeBSD 6.0 may fix the problem, but considering
some of the inevitable bugs that creep into new releases, I'm
reluctant to go there until things settle down in 6.0 (plus, I
haven't seen any documentation that implies that a fix for the
problem will result from using 6.0 in any case). If it weren't a
production machine that needs to be reliable, stable, and available,
I'd have a better chance at being able to test it under 6.0.
Some speculation has been made about it being triggered by possibly
buggy ethernet drivers, etc. In my case, though possible, I doubt it
- since my machine has rebooted itself right when mysqlhotcopy was
about to run on the machine (and it runs locally without causing any
network activity that I'm aware of). The first thought I had was
that it may be caused by faulty memory or something, but Dell's
hardware diagnostics all tested everything to be perfectly okay.
What I find strange is that it's not that the kernel locks up or
anything - the machine just suddenly restarts (caches aren't flushed
to disk or anything - it's just like someone literally pulls the
power plug midstream, and then plugs it back in. The only indication
that something weird goes on is that in the server logs everything
seems to be crunching away happily and then suddenly I see the boot
messages when it restarts all by itself..
In any case, if anyone else with a dual processor machine (I have a
PowerEdge 2850 myself) has experienced the rebooting problem
discussed a few days ago and resolved it, I'd very much like to hear
Syzygy Research & Technology
Box 83, Legal, AB T0G 1L0 Canada
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