KVM is the industry-leading Linux virtualization technology for full virtualization. It's a kernel module, that's merged into the mainline Linux kernel, and it runs with near-native performance on all x86 hardware with virtualization support—either Intel VT-x or AMD-V.

With KVM you can run both Windows and Linux in virtual machines (VMs), where each VM has private, virtualized hardware: a network card, disk, graphics adapter, etc. Running several applications in VMs on a single system, enables you to save power and reduce costs, while at the same time, giving you the flexibility to build an agile and scalable software-defined data center, that meets your business demands.

Container-based virtualization technology is a lightweight alternative to full machine virtualization, because it shares the host system's kernel.

Linux Containers (LXC)

LXC is an operating-system-level virtualization environment for running multiple, isolated Linux systems on a single Linux control host. LXC works as a userspace interface for the Linux kernel containment features. Users can easily create and manage system or application containers with a powerful API and simple tools.

While many people start with a single node, Proxmox Virtual Environment can scale out to a large set of clustered nodes. The cluster stack is fully integrated and ships with the default installation.

Proxmox VE uses the unique Proxmox Cluster File System (pmxcfs), a database-driven file system developed by Proxmox.

With the integrated live/online migration feature, you can move running virtual machines from one Proxmox VE cluster node to another, without any downtime or noticeable effect from the end-user side.

Administrators can initiate this process from either the web interface or the command line. This enables you to minimize downtime, in case you need to take the host system offline for maintenance.

A multi-node Proxmox VE Cluster enables the creation of highly available virtual servers. The Proxmox VE HA Cluster is based on proven Linux HA technologies, providing stable and reliable HA service.

The resource manager, Proxmox VE HA Manager, monitors all VMs and containers in the cluster and automatically comes into action if one of them fails. The Proxmox VE HA Manager works out-of-the-box. Zero configuration is needed. Additionally, the watchdog-based fencing dramatically simplifies deployment.

Proxmox VE includes a HA Simulator. This allows you to test the behavior of a real-world 3 node cluster with 6 VMs. The Proxmox HA Simulator runs out-of-the-box and helps you to learn and understand how Proxmox VE HA works.