Cloning a jail

[Hari Bhaskaran]

Hi,

When I need to clone a jail, would a cp -Rp do?
(and change rc.conf). Or do I have to go through
the jail(8) steps again? (make hierarchy, install etc).
By 'clone', I meant an identical jail session,
on top of which I will install other packages,
not necessarily same on both.

Also can I hardlink a tree (outside) to inside
the jail? assuming I don't mind it being writeable.
Would it open a hole to the rest of the system?

Any help is appreciated
--
Hari Bhaskaran