KVM
Definition
KVM, short for Kernel-based Virtual Machine, is an open-source virtualization technology built into the Linux kernel. It transforms a Linux host into a bare-metal hypervisor, enabling multiple virtual machines (VMs) to run simultaneously with their own operating systems and applications. Each VM uses virtualized hardware components, such as CPUs, memory, storage, and network interfaces.
KVM is widely used in enterprise IT, cloud computing, and data centers because it combines the stability of Linux with near-native performance for virtual machines. It supports a wide range of guest operating systems, including Linux, Windows, and BSD variants, making it a flexible and cost-effective virtualization solution.
Advanced
KVM leverages hardware virtualization extensions such as Intel VT-x and AMD-V to achieve high performance. It integrates closely with QEMU for device emulation, while KVM itself handles CPU and memory virtualization. Advanced features include live migration, snapshots, memory ballooning, and NUMA (Non-Uniform Memory Access) optimization.
KVM is also the foundation for many enterprise-grade virtualization and cloud platforms, including OpenStack, Proxmox VE, and Red Hat Virtualization. With strong community and commercial support, KVM offers scalability for small businesses through to hyperscale cloud providers. Security enhancements, such as SELinux integration and isolation at the kernel level, make it suitable for multi-tenant environments.
Why it matters
Use cases
Metrics
Issues
Example
A telecommunications provider builds its private cloud using Linux servers with KVM and OpenStack. The setup allows rapid provisioning of thousands of VMs for internal services and customer workloads, achieving high scalability with reduced licensing costs.