ZFS Panic after freebsd-update

[Paul Mather]

On Jul 1, 2013, at 11:49 AM, Jeremy Chadwick <jdc at koitsu.org> wrote:

> 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.
>> [[...]]
>> Any thoughts?
> 
> Thoughts:
> 
> [[..]]
> 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.


I'm not sure why it amazes you that people are making widespread use of ZFS.  You could make the same argument that people shouldn't use UFS2 journaling on their file systems because bugs in the implementation might make debugging journaled UFS2 file systems "a serious PITA."  The point is that there are VERY compelling reasons why people might want to use ZFS for root/var/tmp/usr/etc. (pooled storage; easy snapshots; etc.) and there should come a time when a given file system is "generally regarded as safe."  I'd say the time for ZFS came when they removed the big disclaimer from the boot messages.  If ZFS is dangerous, they should reinstate the "not ready for production" warning.  Until they do, I think it's unfair to castigate people for using ZFS universally.

Isn't it a recurring theme on freebsd-current and freebsd-stable that more people need to use features so they can be debugged in realistic environments?  If you're telling them, "don't use that because it makes debugging harder," how are they supposed to get debugged and hence improved? :-)

Cheers,

Paul.