Help to find cause of recurring crash

[Bill Moran]

On Tue, 16 May 2006 21:09:20 +1000
fbsd <fbsd at aanet.com.au> wrote:

> Hello All,
> 
> I'm  running a home email server and twice in the last week it has 
> rebooted itself and been unable to restart due to corruption of the 
> filesystem. I found the following in /var/log/messages
> 
> May 16 17:46:07 hpvectra syslogd: kernel boot file is /boot/kernel/kernel
> May 16 17:46:07 hpvectra kernel:
> May 16 17:46:07 hpvectra kernel:
> May 16 17:46:07 hpvectra kernel: Fatal trap 12: page fault while in 
> kernel mode
> May 16 17:46:07 hpvectra kernel: fault virtual address    = 0x1c
> May 16 17:46:07 hpvectra kernel: fault code        = supervisor write, 
> page not present
> May 16 17:46:07 hpvectra kernel: instruction pointer    = 0x20:0xc062c5e8
> May 16 17:46:07 hpvectra kernel: stack pointer            = 0x28:0xe5079c50
> May 16 17:46:07 hpvectra kernel: frame pointer            = 0x28:0xe5079c64
> May 16 17:46:07 hpvectra kernel: code segment        = base 0x0, limit 
> 0xfffff, type 0x1b
> May 16 17:46:07 hpvectra kernel: = DPL 0, pres 1, def32 1, gran 1
> May 16 17:46:07 hpvectra kernel: processor eflags    = interrupt 
> enabled, resume, IOPL = 0
> May 16 17:46:07 hpvectra kernel: current process        = 52 (vnlru)
> May 16 17:46:07 hpvectra kernel: trap number        = 12
> May 16 17:46:07 hpvectra kernel: panic: page fault
> May 16 17:46:07 hpvectra kernel: Uptime: 5d7h4m50s
> May 16 17:46:07 hpvectra kernel: Dumping 1023 MB (2 chunks)
> May 16 17:46:07 hpvectra kernel: chunk 0: 1MB (159 pages) ... ok
> May 16 17:46:07 hpvectra kernel: chunk 1: 1023MB (261872 pages) 1007 991 
> 975 959 943 927 911 895 879 863 847 831 815 799 783 767 751 735 719 703 
> 687 671 655 639 623 607 591 575 559 543 527 511 495 479 463 447 431 415 
> 399 383 367 351 335 319 303 287 271 255 239 223 207 191 175 159 143 127 
> 111 95 79 63 47 31 15 ... ok
> May 16 17:46:07 hpvectra kernel:
> May 16 17:46:07 hpvectra kernel: Dump complete
> May 16 17:46:07 hpvectra kernel: Automatic reboot in 15 seconds - press 
> a key on the console to abort
> May 16 17:46:07 hpvectra kernel: Rebooting...
> 
> When I turn on the monitor I see that the reboot has not been successful 
> due to "/ was not properly dismounted" and it is asking for fsck to be 
> run manually. When I do that everything is fine again.

You can save yourself some hassle by enabling fsck_y_enable="yes" in
/etc/rc.conf.  If the initial fsck fails, it will try again with fsck -y.
If that fails, you've got serious trouble.

That will make the reboots a _little_ less of a problem for you, but it's
only paint over the rust.  What you really need to do is set up your
system for kernel debugging:
http://www.freebsd.org/doc/en_US.ISO8859-1/books/developers-handbook/kerneldebug.html
This will allow you to collect enough information that a developer can
help.

However, before doing that, I would upgrade to 6.1, in case the problem
has already been fixed.  Additionally, FreeBSD is heavily tested enough
that kernel panics are _usually_ the result of failing hardware.  I'd
get ahold of a memtest86 CD and test your RAM before doing much else.

-- 
Bill Moran
Collaborative Fusion Inc.