Virtualization is the process of creating a software-based, virtual representation of a physical IT resource. Applications, servers, desktops, storage devices and networks can all be virtualized. Virtualization has become the most effective way for businesses of all sizes to reduce IT expenses and increase efficiency. Virtualization can also increase IT agility, flexibility and scalability. Workloads get deployed faster, performance and availability increase, and operations can become automated in a virtualized environment. Virtualization helps simplify IT management, reduce capital and operating costs, minimize downtime and ensure business continuity.
Virtualization uses software to simulate the existence of hardware and create a virtual computer system or virtual machine (VM) that acts like an actual computer. Businesses can run more than one virtual system – and multiple operating systems and applications — on a single physical server, known as the host. Each self-contained VM is completely independent. Software executed on a virtual machine is separated from the underlying hardware resources. Putting multiple VMs on a single computer enables several operating systems and applications to run on just one host machine. A thin layer of software called a hypervisor decouples the virtual machines from the host and dynamically allocates computing resources to each VM as needed. In addition to running multiple operating systems on one physical computer, virtual machines can divide system resources among other VMs for greater load balancing.
For fault tolerance and disaster recovery, virtual machines can be isolated from other software and hardware. The entire state of a virtual machine can be saved to a file, allowing VMs to be copied and moved as easily as moving and copying files. Virtualization allows any virtual machine to be provisioned or migrated to any physical server. This enables server consolidation and lowers hardware costs by using fewer physical machines. IT organizations move workloads to virtual environments to leverage under-utilized hardware, lower hardware acquisition and maintenance costs, save data center space, and reduce power consumption. SUSE Linux Enterprise Server is the most affordable operating system to use in virtual environments, as it ships with Xen and Kernel Virtual Machine (KVM), the two most widely used open source hypervisors.