On Linux, there are applications like kernel (Xen, KVM) allows you to do virtualization on a dedicated server system; a set of applications, especially shared by “box” operating systems which is completely independent of one and other, manage by a “master” for the resource control of each. You can share resources with operating systems so you can create multiple virtual accounts on the same physical server.
The advantage in case of malfunction of your virtual dedicated server is handling the system for maintenance with direct access to storage space to repair it. The whole point of virtual actions to manage through a web interface or ssh to reboot your server instantly.
Applying Xen is available in official package on different Linux distributions, especially on the “Debian Squeeze.” It sets up easily, of course after reading the technical documentation available on the Internet. Hosting companies offer virtual dedicated server solutions pre-configured with a pool of pre-assigned IP on your XEN dedicated server.
The advantage of the hosting virtual application server on dedicated box is; it increases the utilization capacity of resources of dedicated server. With important energy savings, cost effective hosting infrastructure network and server capability able to satisfying customers need, because it is not necessarily to develop the power of resources with this solution. However, when your sites reaches at the limits you will have to consider next level solution.