FreeBSD Boot Environments

[Slawa Olhovchenkov]

I am try to use Boot Environments and have some misundertanding.
As I see beadm manage only zroot/ROOT. But base upgrade touch not only
/{boot,etc,bin,lib,libexec,rescue,sbin} but also /usr and from time to
time /var. And don't touch (at most) /root.

What correct way to use Boot Environments?
Rename zfs datasets as:

From			To
zroot/usr		zroot/ROOT/default/usr
zroot/usr/home		zroot/home

create

zroot/root

leave (rename after moving zroot/usr)

zroot/usr/ports
zroot/usr/src
zroot/usr/local

Or somehow else?

How prepare upgrades for such install?

Create model setup, witch similar enviroment
zfs snap modelroot at N
do install{world,kernel} DESTDIR=/modelroot
do mergemaster -I -U -D /modelroot
zfs send -i N-1 modelroot at N | ssh host zfs recv zroot/ROOT/new

Or somehow else?