A virtual machine (VM) is a software environment that emulates the operation of a physical computer and is capable of running programs the same way as on real hardware. A virtual machine isolates applications and operating systems from the underlying physical hardware, creating an abstraction layer between them.
At the heart of virtualization technology is special software, a hypervisor, which distributes a computer’s physical resources among several virtual machines. The hypervisor creates and manages virtual machines, giving each of them access to the processors, memory, data storage, and network resources of the physical server.
There are two basic types of hypervisors:
- Bare-Metal runs directly on hardware, without the need for an underlying operating system (VMware ESXi, Microsoft Hyper-V, KVM);
- Hosted runs as an application within a traditional operating system (VMware Workstation, Oracle VirtualBox, Parallels Desktop).
Benefits of using virtual machines
- Server consolidation significantly reduces the number of physical servers in an infrastructure by placing multiple virtual machines on a single physical host;
- Isolation and security are provided because each virtual machine functions as a separate entity. A failure or security breach of one VM does not affect other virtual machines running on the same physical server;
- Flexibility and scalability allow you to quickly create, clone, move, and delete virtual machines to meet changing business needs;
- Portability of virtual machines makes it possible to transfer workloads between different physical servers without reinstalling applications, which simplifies infrastructure maintenance and ensures high availability of services;
- Fast disaster recovery is implemented using snapshots of the virtual machine state, which allow you to restore the system in a matter of minutes instead of the hours required to restore the physical server.
Virtual machines remain a fundamental technology in today’s IT infrastructure, providing flexibility, efficiency, and reliability in the deployment and management of computing resources.