Computing hardware continues to evolve, and with today’s machines utilizing multi-core CPUs, high RAM capacity and increased network speed, we have seen the benefits of server virtualization become undeniable. Server virtualization software creates an abstraction layer between the physical server hardware and the operating system software that runs on the server. With virtualization, the physical machine runs a new type of software we call a hypervisor. This hypervisor software enables the installation of multiple operating systems on the same physical server. Each operating system can run both independently and concurrently with the others. To do this, the individual operating system installs have been translated into virtual machines (VMs). Each VM runs its own operating system, applications, and each utilizes some allocated portion of the server’s system resources such as CPU, memory, network access and storage. In short, this allows us to run multiple, unrelated servers (i.e. a Linux web server and a Windows file server) on the same physical server system.
The advantages of server virtualization over traditional installations are numerous. They include improved server hardware utilization which immediately leads to reduced power, cooling, and physical space requirements. These translate to reduced administration and labor costs, reduced time for server and/or application provisioning. Rather than deploying numerous servers that may not be fully utilizing their hardware, server virtualization allows multiple VMs to operate on the same physical server machine. Each virtual machine can interact independently with other devices, applications, data and users as though it were a separate physical resource.
Different virtual machines can run different operating systems and multiple applications while sharing the resources of a single physical computer. Additionally, because each virtual machine is isolated from other virtualized machines, if one crashes, the others are not affected. Centralized storage (e.g. SAN/NAS) in combination with virtualized servers allows for today’s most powerful backup and disaster recovery solutions.