Re: Fatal trap 12 on ZFS in 8.0-RC1

On Oct 25, 2009, at 1:07, Thomas Backman <serenity_at_exscape.org> wrote:

> On Oct 25, 2009, at 3:10 AM, Doug Poland wrote:
>
>> Hello,
>>
>> I'm experimenting with ZFS on 8-0-RC1 (amd64) in a VMWare virtual
>> machine w/2GB RAM.  In installed ZFS on GPT root using the excellent
>> instructions at http://wiki.freebsd.org/RootOnZFS/GPTZFSBoot/RAIDZ1.
>>
>> All was well until I tried some benchmarking with
>> benchmarks/unixbench.  I kept getting kmem_map too small panics on  
>> the
>> filesystem tests so starting playing with vm.kmem_size.
>>
>> I finally got unixbench through the first 6 Filesystem Throughput
>> tests with:
>> vm.kmem_size="1296M"
>> vm.kmem_size_max="1296M"
>> vfs.zfs.arc_max="128M"
>> vfs.zfs.vdev.cache.size="24M" (i think)
>>
>> Unfortunately, ZFS paniced with:
>> Fatal trap 12: page fault while in kernel mode. Now, when I attempt  
>> to
>> restart the VM, as soon as the "boot menu" is gone, I immediately get
>> the same Fatal trap 12 panics again and cannot get past this point.
>>
>> I've got the 8.0-RC1 DVD and can run Fixit, but have no idea how to
>> repair this broken ZFS installation.  Suggestions welcome.
>
> You should be able to break into the loader prompt (choice #6 IIRC)  
> and do
> unset vm.kmem_size
> unset vm...
> ... etc.
> boot
>
> That way, you'll be back to the earlier panics, but at least it'll  
> boot. Oh, and the settings aren't permanent, so make editing /boot/ 
> loader.conf your first prority.
>
> Regards,
> Thomas

Thank you, that worked nicely.