I’ve uploaded to a personal Wiki page
How to create a chroot on openSUSE 12.3
Translation version added to my Unofficial openSUSE Documentation Alternative Translation Project
Assumes the User has no prior knowledge what a chroot is
Very recent information how to invoke the chroot with systemd-nspawn
Updated and current information for installing OpenStack Folsom (with optional Quickstart) into the chroot.
So, why should people consider a chroot?
If you want to run some type of virtualization within an isolated environment (eg OpenStack, KVM, Virtualbox, Xen, VMware, Wine, etc) running virtualization within virtualization can make the environment dog-slow. Chroot is isolation but without paravirtualization which means a virtualization layer is removed so it’s as fast as expected.
You can install multiple instances of openSUSE and even other distros simultaneously. sharing the same kernel but running in their own isolated file system.
almost zero overhead. Whereas even launched but inactive VMs will eat up resources, chroot shares the Host processes directly so processes spin up or shutdown only as needed as happens on a regular system. This is besides the benefits afforded by systemd today.
Although not in this document, it’s possible for the chroot to be an ARM system on an x86 host by using a QEMU modified kernel.