Defining Virtual Private Servers, or VPS?
According to Wikipedia a Virtual Private Server (VPS) sometimes referred to as a Virtual Dedicated Server (VDS) is a method of effectively partitioning a physical server into multiple ‘virtual’ servers that each have the appearance and capabilities of running as a stand alone dedicated machine.
Each virtual server, or VPS hosting environment can run its own stand-alone operating system, and each server may be independently rebooted. This practice of partitioning a single server into multiple ‘virtual’ machines has long been common practice with mainframe computers, but has seen a resurgence lately with the development of virtualisation software and technologies for other architectures, such as virtuzzo, or VM Ware.
The Different Types of Virtual Private Servers
There are 2 kinds of virtualisation: software based and hardware based.
In a software based virtualization environment, the virtual machines share the same kernel and actually require the main node’s resources. Within a hosting environment this aids in real time quota incrementing and decrementing without having to restart the node. Within software based virtualisation, the main examples are Virtuozzo (a Parallals product), and HyperVM (an lxlabs product), and VMWare (a VMWare product).
In hardware based virtualisation, the virtualization mechanism partitions the actual or real hardware resources thereby removing its ability to modify burst or real-time quota modification. These limits are thus hard, and the systems need to be restarted for any modification to take place. Although this method would appear to have a glaring deficiency it tends to be a little more secure and therefore useful in enterprise settings.
Why is VPS is almost as flexible as a dedicated server?
With VPS hosted solutions a user or users can share resources such as the CPU and memory but unlike a shared platform, where you are a virtual host on a shared hardware server, the file systems within the virtual private server’s ‘virtual’ environment are fully partitioned/ partitionable. This means that only you have access to them! This provides you the flexibility to customise your own ‘server’ to your specific needs, adding modules and installing software for your particular requirements.
As cost effective as a shared server
Partitioning a single hardware server into multiple servers has been around for a long time, and is well tried and tested. In fact as we mentioned earlier, mainframe computers have long been partitioned, and so it is a well tried, tested and refined product. Although there are limits to using virtualised platforms, by sharing resources and historically software licensing fees, users are getting far more for their money.