Questions about Jail

[Michael Powell]

James Y Chen wrote:

> Hi
> 
> I think Jail on FreeBSD 8.2 can generate 2 jailed machine using the same
> version of FreeBSD, for example, on a 8.2 AMD64 Jailer, I can create 2
> or more FreeBSD 8.2 amd64 Jailed machine.
> 
> My question is: can I install other version of FreeBSD on the Jailed
> environment? If yes, which steps shall I do? Still using make world or
> other easier way?

In many respects a Jail is more like a super-duper chroot, as opposed to 
other virtualization technologies such as VMWare, Xen, or KVM hypervisor(s). 
The closest parallel is probably Solaris Containers, if you are familiar 
with Solaris.

There will only be one running kernel at the heart of a jail based machine. 
So the bottom line short answer to your question is basically "no".

Possibly you may wish to read this:

http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/jails-intro.html

-Mike