Let's back out LOADER_ZFS_SUPPORT from STABLE

[Daniel Eischen]

On Sat, 13 Jun 2009, Dan Allen wrote:
> How do I get to the old loader when the machine boots and immediately stops? 
> There is no ability at this point in the boot process to try and get to the 
> old loader that I know of.  Is there a hidden magic key combination that 
> allows this?
>
> You are correct that the bulk of the file system is not touched, but the key 
> file partitioning headers get cleared and when you boot off of a DVD -- the 
> only way to get to the system that I know of -- and inspect the file 
> partitioning via whatever means you try, it shows that the root partition is 
> gone.  What was your main file system is gone.  I learned after many installs 
> that I could NOT do a newfs(8) and the setup program would re-mark things and 
> and files ended up re-appearing.
>
> My machine was well backed up so no great loss of data in the end, but it has 
> cost me lots of time to get this figured out.
>
> For me the real questions are these:
>
> * Why is my system the only one that this happens on?
> * What makes my machine setup different?
> * What is the bug in the bootable ZFS loader that munges the partition map?

>From one of your older emails, you mention you are using
ad0s2a as / and ad0s2b as swap, and then say that ad0s2c
is unused (I may have the ad0s2 part wrong).  But ad0s2c
should be the entire slice (or partition depending on
the wording you are used to).

How about posting a relevent fdisk and disklabel (or
gpart show) so we can see what your slices and partitions
look like (fdisk /dev/ad0, disklabel /dev/ad0s2).

-- 
DE