gmirror panic on RELENG_8

[Miroslav Lachman]

Steve Price wrote:
> I installed 8.2-RC1 on a machine with 3 identical drives and got a
> kernel panic when trying to load geom_mirror on boot.  Try as I
> might I've been unable to get a coredump so I can investigate further.
>
> Minimum required to reproduce the error here is to install 8.2-RC1
> from CD and on reboot, drop to the boot loader prompt and type:
>
> load geom_mirror
> boot
>
> da0 contains all of the installed files, da1 was to be a mirror of da0
> so was left alone, and da2 was created as one big partition.
>
> I first noticed this when I installed 8.1-RC1 and then ran the following
> commands after rebooting from the initial install:
>
> sysctl kern.geom.debugflags=17
> gmirror label -vb round-robin gm0 /dev/da0
> echo 'geom_mirror_load="YES"'>>  /boot/loader.conf
> sed -i.bak -e's,da0,mirror/gm0,g' /etc/fstab
> reboot
>
> When the box came back up I got a panic.  I've tried various combos
> to figure out what the minimum was to reproduce this.  I've verified
> that 8.0-RELEASE, and 8.1-RELEASE don't exhibit this same behavior.
>
> If further info is required, please let me know.

There must be some odd problem in your case. I am running 8.2-RC1 with 
gmirror on production machine without any panic. The system was upgraded 
from 7.2.

root at cage ~/# uname -srmi
FreeBSD 8.2-RC1 amd64 GENERIC

root at cage ~/# gmirror status
        Name    Status  Components
mirror/gms1  COMPLETE  ad4s1
                        ad6s1


root at cage ~/# gmirror list
Geom name: gms1
State: COMPLETE
Components: 2
Balance: round-robin
Slice: 4096
Flags: NONE
GenID: 0
SyncID: 1
ID: 3764583301
Providers:
1. Name: mirror/gms1
    Mediasize: 21451497472 (20G)
    Sectorsize: 512
    Mode: r5w5e9
Consumers:
1. Name: ad4s1
    Mediasize: 21451497984 (20G)
    Sectorsize: 512
    Mode: r1w1e1
    State: ACTIVE
    Priority: 0
    Flags: NONE
    GenID: 0
    SyncID: 1
    ID: 1333090696
2. Name: ad6s1
    Mediasize: 21451497984 (20G)
    Sectorsize: 512
    Mode: r1w1e1
    State: ACTIVE
    Priority: 0
    Flags: NONE
    GenID: 0
    SyncID: 1
    ID: 1584887928


root at cage ~/# kldstat
Id Refs Address            Size     Name
  1   21 0xffffffff80100000 da0458   kernel
  2    1 0xffffffff80ea1000 21068    geom_mirror.ko
  3    1 0xffffffff81022000 104a7a   zfs.ko
  4    1 0xffffffff81127000 1a22     opensolaris.ko
  5    1 0xffffffff81129000 57d7     if_bridge.ko
  6    1 0xffffffff8112f000 3536     bridgestp.ko
  7    1 0xffffffff81133000 264e     if_tap.ko
  8    1 0xffffffff81136000 2bd81    pf.ko
  9    1 0xffffffff81162000 1fde     nullfs.ko


gmirror is loaded from loader.conf

root at cage ~/# grep -v ^# /boot/loader.conf

hw.bge.allow_asf="1"

geom_mirror_load="YES"

vm.kmem_size="1280M"
vm.kmem_size_max="1280M"
kern.maxvnodes="400000"
vfs.zfs.prefetch_disable="1"
vfs.zfs.arc_min="64M"
vfs.zfs.arc_max="512M"

kern.ipc.semmni=100
kern.ipc.semmns=1000
kern.ipc.semmnu=300

Miroslav Lachman