[install-discuss] ZFS install into an existing root pool

[timeless]

I have an existing root pool (across 2 disks) and no spare space
outside the pool... Is there a provision with the new installer to
install into such a pool? If not, could someone give me pointers to
how I might go about adding this and a suggestion about how much work
it would take (just order of magnitude: days, weeks, months)?