Solaris live upgrade like FreeBSD ZFS-rootfs update

Hi,

I'm playing a lot with ZFS root filesystems for FreeBSD and using
zfsboot with GPT. So far it works perfecly for me on three not-so
production servers and I would like to thank everybody that helped make
this work!

With ZFS suddenly some neat stuff is easly possible with FreeBSD, like
the Solaris Live Upgrade feature. The idea behinde Live Upgrade is that
you have more than one bootable-environment to boot from making it very
painless to upgrade to newer FreeBSD versions without loosing the
possibility to boot your known-good boot-environemt. So you can't end up
with a broken userland or kernel and you can even go back to your old
userland and kernel if the new ones do not work for you.

Particularly with tracking CURRENT this becomes very handy!

I wrote a shell script to create, activate and delete boot-environments
in FreeBSD. Its far from feature complete and some bits are still
missing but creating and activating boot-environments should be more or
less feature-complete.

In case anyone is interested or maybe wants to base a FreeBSD
userland-tool on it, take a look at http://outpost.h3q.com/patches/manageBE/

Bug reports and suggestions are welcome!

Biggest part that is missing in the ZFSboot stuff right now is being
able to choose from the available boot-environments in the loader. If
that would work, updating a FreeBSD box would be down to one reboot
without any risk.

greetings,
cryx