Virtual Server

Introduction

A Virtual Server or Virtual Private Server (VPS) or Virtual Dedicated Server (VDS) is a way of converting one physical server into multiple virtual servers that can run on different operating systems and configurations. Each virtual servers runs in its own partition and can be rebooted independently. In the case of failure, the other virtual servers on the same physical machine are not affected. It looks and feels like a "real" independent server, but in reality is just a piece of software running in a sandbox.

This is achieved by using virtualization software such as VMware or Microsoft Virtual Server to name just two. There are many different products on the market today and we will soon publish an overview and comparison of the most important ones. In the meantime, you can find an exhaustive list here.

Overview of Virtual Server technology

The Virtual Server emulation Software needs a host operating system that allows the physical machine to boot normally. During the start-up process, a program is executed that boots each virtual server independently. The virtual servers have no direct access to the hardware level and are run from a disk image. An important issue is to keep performance overhead introduced by virtualization small, so that server resources can be efficiently used by the virtual servers.

Two main categories of virtualization technologies exist:

• Software based
  Sharing the same kernel and using resources of the main node. Used in Web Hosting environments with products such as Virtuozzo (swsoft.com) and HyperVM (lxlabs.com) which both use the OpenVZ as the core kernel.
  
• Hardware based
  Hardware based virtualization partitions the available hardware resources and assign them to the individual Operating Systems running on the physical server. Mainly used in enterprise/commercial environments. Examples include Microsoft Virtual Server, VMware ESX Server and the Xen™ virtual machine.
  

Advantage of the Virtual Server

Shared and dedicated hosting both have their advantages. Shared hosting is an inexpensive way to run many websites on one physical machine. As all the sites share the same hardware and operating system, one application can end the life of all. Dedicated Hosting means running your own server to avoid this risk of sharing resources. This comes at a high price, so Virtual Servers fill the gap and offer independence at a lower cost. Each instance of the operating system running on the physical server is configured independently form another. So each one can be assigned different users and user rights. There can even be a mix of operating systems running in sandboxes of the same physical server. The server might boot in a flavor of Linux and have Virtual Servers running Windows. A blue screen in one instance would mean rebooting that virtual server instance only without affecting the other Virtual Servers or the host operating system. Nice.

Virtual Server Hosting

Virtual Server Hosting has become very popular and there are many different offers on the market. Starting at around $ 25 a month, you get an independent Virtual Private Server with full root access.

We are currently testing some of the best offers and will shortly share our experiences. In the meantime, you are welcome to let everyone know about your experiences and recommendations. Please use the forum for your feedback.