CONFINE YOUR SOFTWARE
Jails are FreeBSD's most legendary feature: known to be powerful, tricky to master, and cloaked in decades of dubious lore. Deploying jails calls upon every sysadmin skill you have, and more--but unleashing lightweight virtualization is so worth it.
FreeBSD Mastery: Jails cuts through the clutter to expose the inner mechanisms of jails and unleash their power in your service. You will:

• Understand how jails achieve lightweight virtualization
• Understand the base system's jail tools and the iocage toolkit
• Optimally configure jail hardware
• Manage jails from the host and from within the jail
• Optimize disk space usage to support hundreds or thousands of jails
• Comfortably work within the limits of jails
• Implement fine-grained control of jail features
• Build virtual networks
• Deploy hierarchical jails
• Constrain jail resource usage
• And more

Strip away the mystery. Read FreeBSD Mastery: Jails today
"This is the sequel to Git Commit Murder, right ?"
/phk, creator of the jail system