In past editions of “Cloudy to Clear,” we’ve defined terms related to the cloud’s deployment methods (public, private, hybrid), architectures (SaaS, PaaS, IaaS), and basic characteristics (API, reliability, scalability, multi-tenancy). Today we’ll turn our focus to terms related to virtualization.
Cloud computing might not exist without virtualization. Virtualization accounts for the cloud’s reliability, scalability, and multi-tenancy. Without it, the cloud would be indistinguishable from older, less efficient types of web-based hosting. Not all forms of virtualization relate to cloud computing, but almost every form of cloud computing requires virtualization.
Virtualization. This blogger defines virtualization as “a framework or methodology of dividing the resources of a computer into multiple execution environments, by applying one or more concepts or technologies such as hardware and software partitioning, time-sharing, partial or complete machine simulation, emulation, quality of service, and many others.” In a normal computing environment, the operating system has an indivisible 1:1 ratio with its hardware. In contrast, virtualization platforms allow multiple, distinct computing environments to operate on a single hardware system (or “core”).
People may confuse a Windows operating system that allows a user to utilize different “computing environments” in the form of programs like Microsoft Word and Excel as a type of virtualization. But this view overlooks two important aspects of the technology: 1) Virtualization allows numerous computing environments (such as an OS) that would normally require a 1:1 ratio with a dedicated hardware system to run simultaneously on the same hardware. Applications, much less integrated with the hardware and requiring less computing resources, already have a many-to-one ratio with their hardware system in a normal computing environment. 2) A hardware system gives highest priority to the function of its dedicated operating system. Virtualization tricks the hardware system into giving #1 priority to multiple virtual operating systems. If the virtual operating systems shared the same priority level and access to the resources of the hardware as applications, they would not have the processing power to be functional.
Cloud computing relies on virtualization technologies in a number of ways. Virtualization’s ability to compress multiple computing environments into a single hardware system, combined with the slight disassociation of the virtual machines from the hardware, allows the cloud to: 1) host a large number of infrastructure and application deployments on a small number of servers; 2) maximize computing resources by intuitively transferring or prioritizing virtualized deployments; 3) ensure security by isolating, deleting, and replacing infected virtual machines; 4) centralize control of an entire virtualized infrastructure, making system-wide repairs, upgrades, scaling, and backups faster and easier.
Outside of cloud computing, virtualization also allows people to switch operating systems; to test applications in a stable and controlled environment; and to perform inherently insecure tasks in a contained environment.
Desktop virtualization. A type of virtualization. With regular virtualization, the hardware hosting and the hardware utilizing the virtual machines are the same. With desktop virtualization, external hardware connects over the Internet to the hosting hardware to utilize the virtual machines. IronOrbit provides virtual desktop infrastructures (VDIs) for most of its customers.
Hypervisor. The platform that creates, contains, prioritizes, and manages the virtual computing environments or virtual machines (VMs). The two types of virtualization hypervisors are bare metal and hosted. Bare metal installs directly onto the hardware, while hosted integrates with an already-installed operating system. Bare metal hypervisors provide superior performance speeds and administrative access. IronOrbit employs the industry-leading VMware ESXi bare metal hypervisor on all its deployments.