Virtualisation is a technology that creates virtual representations of computing resources, including servers, storage, and networks. It essentially partitions a single physical machine's hardware components—processors, memory, and storage—into multiple Virtual Machines (VMs). Each VM acts as an independent computer, running its own Operating System (OS) and applications, isolated from other VMs on the same physical machine.
This is achieved through a software layer called a hypervisor. The hypervisor sits directly on the physical hardware and manages the allocation of resources to each VM. It ensures that each VM receives the necessary CPU, memory, and storage to function while preventing VMs from interfering with each other.
There are two main types of hypervisors: Type 1 (bare-metal) hypervisors run directly on the physical hardware, providing the most direct access to resources for VMs. Type 2 (hosted) hypervisors run on top of an existing operating system, offering greater flexibility for deploying VMs on existing infrastructure.
Virtualisation offers several advantages:
- Increased resource utilisation: By consolidating workloads onto fewer physical machines, virtualisation optimises hardware usage and reduces energy consumption.
- Improved agility: VMs are portable and can be easily migrated between physical machines, enabling faster provisioning and disaster recovery.
- Isolation and security: VMs are isolated from each other, enhancing security and reducing the risk of application conflicts.
- Cost savings: Virtualisation lowers hardware costs by maximising utilisation and reducing the need for dedicated physical servers.
Overall, virtualisation is a cornerstone technology in modern IT, enabling efficient resource management, improved agility, and cost savings. It plays a critical role in cloud computing, where virtualised resources are delivered as services on demand.
