Virtualization optimizes the use of IT resources and consolidates servers in the data center. This creates the necessary foundation for effective, scalable, and simplified delivery of Cloud services. But, how is virtualization done?
At the outset it must be understood that anything can be virtualized—memory, networks, storage, hardware, operating systems or applications. This is because, virtualization enables partitioning, isolation and encapsulation. Partitioning enables organization of a single system into what seems to be multiple units. Isolation enables the segregation of virtual machines such that each machine is independently protected by abstracting the software from the hardware. A cyber attack on one virtual machine will not affect other virtual machines on the same physical system. Encapsulation is the process of protecting individual applications on a virtual machine vis-à-vis other applications on the machine or a virtual machine itself can be represented as a single file on a physical server, separated from other similar virtual machine “files”.
Organizations attempting to virtualize their data centers use hypervisors to facilitate the process. A hypervisor, also known as Virtual Machine Monitor (VMM) can be software, firmware or hardware that helps create virtual machines. The computer that runs the virtual machine is known as the host machine and each virtual machine is labeled a guest machine. Each guest machine has a virtual operating system and all guest virtual machines will share the same hardware resources. As a result, hypervisors can support a number of operating environments and can be an ideal mechanism for delivering a variety of applications to end users.
Hypervisors are generally classified as Type 1 or Type 2 hypervisors.
Type 1 hypervisor is a “bare metal” installation. A bare metal installation is an installation of the hypervisor directly on the hardware. It runs from the hardware and is the first software to be installed (even before the operating system is installed). The strength of this type of hypervisor is that is interacts directly with the underlying physical hardware.
Type 2 Hypervisor is also known as the hosted hypervisor. The hypervisor software is loaded on top of an operating system that is already in operation. For instance, you can install VMware Workstation 8 on top of Windows Server 2008 R2. However, the resulting latency is negligible. The guest Virtual machine will continue to act independent of the operating system on which the hypervisor runs.
It is obvious that the virtualization of the data center prior to transitioning computing to the Cloud is an intelligent and sensible way to go. A lot of work gets done in-house and a number of space-saving and cost saving activities get done upfront.