using zfs and unionfs together, does zfs need to be extended?

[Kris Kennaway]

George Hartzell wrote:
> I'd like to be able to set up a large-ish number of very similar
> jails, with a minimum of fuss and take advantage of zfs' cool
> features.  I'd like to use unionfs to do this, but zfs' lack of
> whiteout support seems to make it impossible.  [jump to the bottom if
> you want to skip the setup and get to the questions]
> 
> It seems like the most popular way to set up jails these days uses
> read-only nullfs mounts of a base system and symbolic links into a
> read-write nullfs mount for each jail's specific stuff (etc,
> /usr/local, etc...).

The "ZFS way" is to just clone your jail filesystem into each jail instance.

Kris