Server crash by disconnecting nfs?

Tue Jun 20 08:53:06 UTC 2006

Some days ago we had a strange reboot of one of our production servers.
After closing the nfs-connection to our FreeBSD machine the
FreeBSD machine produced a core dump and booted. Though we are
not quite sure if the disconnection was the actual cause of the core
dump we know
at least that both things happened within the same time frame
of about 15 minutes.

Now we would like to know the reason why the machine crashed
(it was running without problems since months)

We looked into the dump file, but we can't really understand
the information displayed there. Can someone give us some hints how to
find out what happened.

Thanks
Norbert

machine architecture
--------------------
5.4-RELEASE-p8 
i386
Intel(R) Xeon(TM) CPU 3.00GHz
hw.physmem: 3480444928

Dump info file
--------------
Dump header from device /dev/amrd0s1b
  Architecture: i386
  Architecture Version: 16777216
  Dump Length: 3489398784B (3327 MB)
  Blocksize: 512
  Dumptime: Fri Apr 28 15:52:21 2006
  Hostname: host.testserver.de
  Magic: FreeBSD Kernel Dump
  Version String: FreeBSD 5.4-RELEASE-p8 #2: Tue Nov 15 17:35:15 CET
2005
    root at host.testserver.de:/mnt/data/obj/mnt/data/src/sys/GT
  Panic String: page fault
  Dump Parity: 590850776
  Bounds: 58
  Dump Status: good

kgbd stack backtrace
--------------------
#0  doadump () at pcpu.h:159
#1  0x9c530806 in boot (howto=260) at
/mnt/data/src/sys/kern/kern_shutdown.c:410
#2  0x9c530bf4 in panic (fmt=0x9c6e2059 "%s") at
/mnt/data/src/sys/kern/kern_shutdown.c:566
#3  0x9c6bd85c in trap_fatal (frame=0xda4748f4, eva=0) at
/mnt/data/src/sys/i386/i386/trap.c:817
#4  0x9c6bd512 in trap_pfault (frame=0xda4748f4, usermode=0, eva=28) at
/mnt/data/src/sys/i386/i386/trap.c:735
#5  0x9c6bd0bf in trap (frame=
      {tf_fs = -1588199400, tf_es = -1670184944, tf_ds = -1594753008,
tf_edi = -1595176448, tf_esi = -1597679616, tf_ebp = -632862380, tf_isp
= -632862432, tf_ebx = -1595176448, tf_edx = 0, tf_ecx = -1588166656,
tf_eax = 4, tf_trapno = 12, tf_err = 2, tf_eip = -1672419718, tf_cs = 8,
tf_eflags = 66118, tf_esp = -632862364, tf_ss = -1672340506})
    at /mnt/data/src/sys/i386/i386/trap.c:425
#6  0x9c6a7f3a in calltrap () at
/mnt/data/src/sys/i386/i386/exception.s:140
#7  0xa1560018 in ?? ()
#8  0x9c730010 in swap_pager_almost_full ()
#9  0xa0f20010 in ?? ()
#10 0xa0eb8a00 in ?? ()
#11 0xa0c55800 in ?? ()
#12 0xda474954 in ?? ()
#13 0xda474920 in ?? ()
#14 0xa0eb8a00 in ?? ()
#15 0x00000000 in ?? ()
#16 0xa1568000 in ?? ()
#17 0x00000004 in ?? ()
#18 0x0000000c in ?? ()
#19 0x00000002 in ?? ()
#20 0x9c50e67a in knote (list=0xa0eb8a98, hint=0, islocked=0) at
atomic.h:365
#21 0x9c56afbe in ttwwakeup (tp=0xa0eb8a00) at
/mnt/data/src/sys/kern/tty.c:2394
#22 0x9c69367e in comstart (tp=0xa0eb8a00) at
/mnt/data/src/sys/dev/sio/sio.c:2514
#23 0x9c692ffb in comparam (tp=0xa0eb8a00, t=0xa0eb8aa4) at
/mnt/data/src/sys/dev/sio/sio.c:2350
#24 0x9c691756 in sioopen (dev=0x9c742ad0, flag=3, mode=8192,
td=0xa1568000) at /mnt/data/src/sys/dev/sio/sio.c:1292
#25 0x9c4e3e4a in spec_open (ap=0xda474a6c) at
/mnt/data/src/sys/fs/specfs/spec_vnops.c:207
#26 0x9c4e3af8 in spec_vnoperate (ap=0x0) at
/mnt/data/src/sys/fs/specfs/spec_vnops.c:118
#27 0x9c5a7eee in vn_open_cred (ndp=0xda474bd8, flagp=0xda474cd8,
cmode=3112, cred=0xa0b17780, fdidx=0) at vnode_if.h:228
#28 0x9c5a7a83 in vn_open (ndp=0x0, flagp=0x0, cmode=0, fdidx=0) at
/mnt/data/src/sys/kern/vfs_vnops.c:91
#29 0x9c5a03d3 in kern_open (td=0xa1568000, path=0x0,
pathseg=UIO_USERSPACE, flags=3, mode=-1681920472) at
/mnt/data/src/sys/kern/vfs_syscalls.c:957
#30 0x9c5a02b0 in open (td=0x0, uap=0x0) at
/mnt/data/src/sys/kern/vfs_syscalls.c:926
#31 0x9c6bdc70 in syscall (frame=
      {tf_fs = 47, tf_es = 47, tf_ds = 47, tf_edi = 134545056, tf_esi =
0, tf_ebp = -1681920472, tf_isp = -632861324, tf_ebx = -1681920304,
tf_edx = 134536656, tf_ecx = 0, tf_eax = 5, tf_trapno = 12, tf_err = 2,
tf_eip = 671983903, tf_cs = 31, tf_eflags = 642, tf_esp = -1681920500,
tf_ss = 47}) at /mnt/data/src/sys/i386/i386/trap.c:1009
#32 0x9c6a7f8f in Xint0x80_syscall () at
/mnt/data/src/sys/i386/i386/exception.s:201
#33 0x0000002f in ?? ()
#34 0x0000002f in ?? ()
#35 0x0000002f in ?? ()
#36 0x0804fea0 in ?? ()
#37 0x00000000 in ?? ()
#38 0x9bbfee28 in ?? ()
#39 0xda474d74 in ?? ()
#40 0x9bbfeed0 in ?? ()
#41 0x0804ddd0 in ?? ()
#42 0x00000000 in ?? ()
#43 0x00000005 in ?? ()
#44 0x0000000c in ?? ()
#45 0x00000002 in ?? ()
#46 0x280da91f in ?? ()
#47 0x0000001f in ?? ()
#48 0x00000282 in ?? ()
#49 0x9bbfee0c in ?? ()
#50 0x0000002f in ?? ()
#51 0x00000000 in ?? ()
#52 0x00000000 in ?? ()
#53 0x00000000 in ?? ()
#54 0x00000000 in ?? ()
#55 0x1711e000 in ?? ()
#56 0xa1b8d388 in ?? ()
#57 0xa1568000 in ?? ()
#58 0xda47474c in ?? ()
#59 0xda474730 in ?? ()
#60 0xa0b9b180 in ?? ()
#61 0x9c545040 in sched_switch (td=0x0, newtd=0x9bbfeed0, flags=Cannot
access memory at address 0x9bbfee38
) at /mnt/data/src/sys/kern/sched_4bsd.c:881
Previous frame inner to this frame (corrupt stack?)