Virtual Private Servers or VPS is the method by which many virtual servers are partitioned out of a single physical server. This will help the users to get many logical servers when the actual cost of the server is very high. The virtual servers are independent with their own operating system and resources. They can work on their own and even reboot without assistance from the main physical server. VPS is highly useful in web sites hosting where the clients can work on multiple servers simultaneously without any failure.

 When understanding the concept of VPS, users are required to understand the term burstable memory. It is often confused with guaranteed memory even though there is considerable difference between the two. Guaranteed memory is defined as the usable memory out of the memory available in VPS. This is available for the user at all time. Very often this guaranteed memory can be changed to burstable memory by the VPS.

Burstable memory set a maximum limit for the memory available where as guaranteed memory is a minimum limit. That is, even if the guaranteed memory is exhausted, the users of VPS can use the memory up to the limit of burstable memory. The simplest example to understand the difference is: if the guaranteed memory of a VPS is 256mb and the burstable memory limit is 1024 mb, the users can use the remaining 768MB RAM once their guaranteed memory is completely used up. This is possible only if the host server has that much memory available with it.

It is always a procedure to keep certain part of the memory in host server as burstable. This can be used by the virtual servers when they are in need of extra memory. Also the guaranteed memory unused in any virtual server can be used by other virtual servers when they want burstable memory. It is known that guaranteed memory should be available for use for the virtual servers. So when they are in need of guaranteed RAM, they usually kill the processes that use their memory as burstable to get the memory released. So it is always better not to use the burstable memory unless it is so needed.

When trying to get a VPS server, it should be clearly understood that the memory availability that they demand is not burst memory. The guaranteed memory must be available in sufficient amount to get proper working in VPS. The memory burstable is not readily available always as it can be obtained only on a lapse of guaranteed memory by other virtual servers in the system.

When choosing the platform for VPS hosting, there should be a proper analysis of the memory availability. The Linux and Windows platform allow for using the extra guaranteed memory as burtsable. This is very essential for the use of the VPS for web site hosting. Memory should be the bottle neck in choosing the right virtual private server for web site hosting.