Changes

Virtualization is made possible by the ability of the kernel to dynamically change the current root filesystem (a concept known as chroot) to a different root filesystem without having to reboot the entire system. In simple terms, shared kernel virtualization is an extension of this capability which allows multiple instances of an operating system to run on a single physical host. Perhaps the biggest single draw back of this form of virtualization is the fact that the guest operating systems must be compatible with the version of the kernel which is being shared. It is not, therefore, possible to run Windows as a guest on a Linux system using the shared kernel approach. Nor is it possible for a Linux guest system designed for the 2.6 version of the kernel to share a 2.4 version kernel.

== Kernel Level Virtualization ==