ZFS: amd64, devd, root file system.

Hi.

Just a quick summary on recently committed changes:

1. ZFS can now be used on amd64. Thanks goes to des and kan for testing.

2. I added sample entries to devd.conf, which show how to handle
   problems reported by ZFS, like I/O failures, VDEV failures, checksum
   mismatches, etc.

3. It is now possible to have root file system on ZFS. You would still
   need UFS for your /boot/ file system.

Location of zpool.cache file has changed from /etc/zfs/ to /boot/zfs/.
To avoid any troubles you should:

	# zpool export <your pools>
	# kldunload zfs
	# mv /etc/zfs/zpool.cache /boot/zfs/
	# make kernel
	# kldload zfs
	# zpool import <your pools>

If you won't do it, /etc/rc.d/zfs most likely won't mount your file
systems and you would need to do:

	# zpool import -f <your pools>

by hand once. Don't forget to remove /etc/zfs/zpool.cache - it will no
longer be needed.

-- 
Pawel Jakub Dawidek                       http://www.wheel.pl
pjd_at_FreeBSD.org                           http://www.FreeBSD.org
FreeBSD committer                         Am I Evil? Yes, I Am!