ZFS Panic after freebsd-update

[Jeremy Chadwick]

On Mon, Jul 01, 2013 at 11:35:30AM -0400, Scott Sipe wrote:
> *** Sorry for partial first message! (gmail sent after multiple returns
> apparently?) ***
> 
> Hello,
> 
> I have not had much time to research this problem yet, so please let me
> know what further information I might be able to provide.
> 
> This weekend I attempted to upgrade a computer from 8.2-RELEASE-p3 to 8.4
> using freebsd-update. After I rebooted to test the new kernel, I got a
> panic. I had to take a picture of the screen. Here's a condensed version:
> 
> panic: page fault
> cpuid = 1
> KDB: stack backtrace:
> #0 kdb_backtrace
> #1 panic
> #2 trap_fatal
> #3 trap_pfault
> #4 trap
> #5 calltrap
> #6 vdev_mirror_child_select
> #7 ved_mirror_io_start
> #8 zio_vdev_io_start
> #9 zio_execute
> #10 arc_read
> #11 dbuf_read
> #12 dbuf_findbp
> #13 dbuf_hold_impl
> #14 dbuf_hold
> #15 dnode_hold_impl
> #16 dnu_buf_hold
> #17 zap_lockdir
> Uptime: 5s
> Cannot dump. Device not defined or unavailable.
> Automatic reboot in 15 seconds - press a key on the console to abort
> 
> uname -a from before (and after) the reboot:
> 
> FreeBSD xeon 8.2-RELEASE-p3 FreeBSD 8.2-RELEASE-p3 #0: Tue Sep 27 18:45:57
> UTC 2011     root at amd64-builder.daemonology.net:/usr/obj/usr/src/sys/GENERIC
>  amd64
> 
> dmesg is attached.
> 
> I was able to reboot to the old kernel and am up and running back on 8.2
> right now.
> 
> Any thoughts?

Thoughts:

- All I see is an amd64 system with 16GB RAM and 4 disks driven by an ICH10
  in AHCI mode.

- Output from: zpool status

- Output from: zpool get all

- Output from: zfs get all

- Output from: "gpart show -p" for every disk on the system

- Output from: cat /etc/sysctl.conf

- Output from: cat /boot/loader.conf

- Is there a reason you do not have dumpdev defined in /etc/rc.conf (or
  alternately, no swap device defined in /etc/fstab (which will get
  used/honoured by the dumpdev="auto" (the default)) ?  Taking photos of
  the console and manually typing backtraces in is borderline worthless.
  Of course when I see lines like this:

  Trying to mount root from zfs:zroot

  ...this greatly diminishes any chances of "live debugging" on the
  system.  It amazes me how often I see this come up on the lists -- people
  who have ZFS problems but use ZFS for their root/var/tmp/usr.  I wish
  that behaviour would stop, as it makes debugging ZFS a serious PITA.
  This comes up on the list almost constantly, sad panda.

- Get yourself stable/9 and try that:
  https://pub.allbsd.org/FreeBSD-snapshots/

- freebsd-fs is a better place for this discussion, especially since
  you're running a -RELEASE build, not a -STABLE build.

-- 
| Jeremy Chadwick                                   jdc at koitsu.org |
| UNIX Systems Administrator                http://jdc.koitsu.org/ |
| Making life hard for others since 1977.             PGP 4BD6C0CB |