Virtual Server Definition
The term virtual server refers to a number of distinct technologies. Here we examine the type of virtual server known as the Virtual Private Server (VPS), otherwise called a Virtual Dedicated Server (VDS). This type of virtual server is a method of dividing a single server machine into multiple servers by employing virtual machines. Each virtual server has its own operating system (OS) and server administrators can reboot and operate on them independently.
Data centers have financial and physical limitations. VPSs overcome some of these limitations by reducing the physical footprint and achieving cost effectiveness through consolidation. Shared server solutions are an alternative to a VPS that also help to overcome these limitations. The advantages and disadvantages that we consider here are those of a VPS contrasted against a shared server solution.
The core advantages of a VPS are cost, independence, insulation, performance and security. Independence and insulation are what make a VPS a practical solution. A VPS essentially provides all of the benefits of operating one server per machine and insulation, in a virtual way, provides the same boundaries that exist between servers in separate machines. This limits the disadvantages that the system introduces. It also allows performance to be higher because there are no bottlenecks introduced from the coordination of resources. In addition, there is no threat of a compromised server influencing any of the other servers on its machine.
One of the core disadvantages of a VPS is the ability to adapt to load. During periods of high traffic, a server in a shared environment can borrow the resources of its fellow servers in order to handle the additional load. In general, VPSs and one-server-per-machine environments are more wasteful than shared solutions. Resources often go unused and the data center must account for far greater resources than they would use in a shared scenario due to individual peak levels.