It is possible to spawn a completely jailed second (or many!) operating system within a modern FreeBSD install. Doing so can be tricky, but here I will document the method that I have found works for me. The first most important resource about jails, is the man page, and many of the examples that you will see are basically straight following of the man page. Once you are done, each jail will operate as if its a complete independant operating system.
Scope Of This Document
This Howto article is intended to be a practical example, and I will start my host system with FreeBSD 6.2-RELEASE. The Install will be of the “minimal” variety, and for the first part of this document, we will not update the system with buildworld. After a jail is created, we will then update the host, and then update the jail. This will demonstrate a practical example of how to build, and then maintain a jail thru critical security releases.