FreeBSD Crash without Errors, Warnings, or Panics
jhb at freebsd.org
Thu Apr 13 18:38:21 UTC 2006
On Thursday 13 April 2006 14:17, Matthew Hagerty wrote:
> I'm running 6.0-RELEASE-p5 on a Toshiba built server: dual Xeon Intel
> motherboard with a LSILogic MegaRAID (amr0) controller. This machine
> has been running for about 2 years now, and was very stable until I
> updated from 5.3 to 5.4, and now 6.0. The crashing seems to be totally
> random and I have had it crash in as little as 12 hours and as long as
> 143 days.
> When the box goes down it does so in a strange way. First, it still
> responds to network probes like ping (usually), however, all console
> access is ignored. Also, some network ports still respond, like a
> telnet to port 22 to test SSH will yield an SSH banner, but trying to
> connect with SSH just hangs. Sometimes this is also true of the SMTP
> server, but not always. This also makes it impossible for me to use
> CARP to swap to the recently purchased spare machine, since the network
> interface is generally still responding so CARP does not detect a problem.
> My biggest problem with this is that there are *never* any console
> messages or log entries in any logs, no warnings about disk failure,
> buffer exhaustion, system failures, etc.. The machine simply seems to
> stop responding and the only way to correct the problem is a hard reboot.
> A strange thing did happen yesterday though, I believe I caught the box
> on the verge of failure. I was SSH'd in and did a ps to check things
> out. There were about 100 of these entries:
> 55050 ?? D 0:00.00 postmaster: ipa ipa ::1(63061) startup (postgres)
> The box runs a web-based app and connects to a local Postgres DB which
> seemed to be unable to start new connections being requested by the PHP
> scripts. At any rate, I stopped Apache and then tried to stop Postgres
> which resulted in (or just happened to coincide with) the box locking up
> and no longer responding to my SSH commands or attempts to reconnect
> with SSH. I hardly think this is a Postgres problem, but even if it
> was, a userland app should *not* be able to bring down a box...
> Can anyone shed some light on this, give me some options to try? What
> happened to kernel panics and such when there were serious errors going
> on? The only glimmer of information I have is that *one* time there was
> an error on the console about there not being any RAID controller
> available. I did purchase a spare controller and I'm about to swap it
> out and see if it helps, but for some reason I doubt it. If a
> controller like that was failing, I would certainly hope to see some
> serious error messages or panics going on.
> I have been running FreeBSD since version 1.01 and have never had a box
> so unstable in the last 12 or so years, especially one that is supposed
> to be "server" quality instead of the make-shift ones I put together
> with desktop hardware. And last, I'm getting sick of my Linux admin
> friends telling me "told you so! should have run Linux...", please give
> me something to stick in their pie holes!
It sounds like a livelock (or deadlock) more than a crash. Can you add
'DDB' in your kernel config and break into the debugger when it hangs
and grab the output of 'ps'?
John Baldwin <jhb at FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve" = http://www.FreeBSD.org
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