bootless!

[Randy Bush]

>> i386 running 7.2 as of aug 29
>> twe, gmirrored boot partition, zfs universe
>> cvsupped 24 hours ago
>> new kernel world
>> will not boot.  get beastie but stops at first twirly
>> 
>> can boot old kernel -s, but not new kernel
>> 
>> can not use old kernel with new world, hangs if i try to /etc/rc.d/zfs
>> start
> 
> A few questions:  Have you cvsupped to 7-STABLE or 8?  Are you using ZFS
> root?  Do you get anything extra with "boot -v"?  Have you tried your
> old loader (/boot/loader.old)?

really dead ended with old systems.  no, root not zfs.

the post mortem by a friend:

friday morning, while trying to solve some other problem (i no longer
remember what), randy did a "make installworld" that broke psg.com's
ability to use its zfs filesystems.  obvious answer was to revert, but
that turns out to be easier to say than to do with /usr offline.

friday's attempts to roll back via net and remote hands failed, so
randy diverted to seattle.

after further whackiness on saturday with randy in the westin with a
crash cart, it became clear that, even using the pre-zfs filesystems
that had been sitting idle since the move to zfs, the machine was too
messed up to be able to run "make world".  many programs (eg, "ln")
were failing with sigsys errors due to some kind of mismatch between
userland and kernel.

so we installed freebsd 7.2 from distro media onto a blank usb hard
drive, whacked the bios with a club until it admitted to being able to
boot from usb, and used that disk as a stable build platform capable
of running csup and make world.  this didn't solve the problem, but
got us far enough that randy could check out of the westin.

after further antics, gyrations, sacrifices of rubber chickens, and
some sleep, we finally got zfs back up, installed new world and
kernel, fixed all the things we had broken (well, that we could
remember or had logged), and got the machine back up and running on
its filesystems, with just enough time left for randy to eat dinner
and head for the ferry to catch a red eye bound for nanog.

so that's where we are now: randy's in transit and everything seems
back to normal.  initially exim was groaning under the load of a
weekend's mail backlog, but that looks to be calming down.

-30-