A hypervisor is software that manages virtual machines and allocates the physical server's processor, memory, and disk between them. Hypervisors fall into two types based on where they run: directly on the hardware or on top of a regular operating system. The difference affects performance, the density of virtual machines on a server, and the set of available features.
How a type 1 hypervisor differs from type 2
A type 1 hypervisor, also called bare-metal, installs directly on the physical server and becomes the operating system for the virtual machines itself. Requests to the processor and memory go directly, without an intermediary. A type 2 hypervisor installs as a regular program on top of an operating system that is already running — Windows, Linux, or macOS — and reaches the hardware through it.
- type 1 starts before any other operating system loads and works with the hardware directly
- type 2 runs as a process inside the host OS and depends on its scheduler and drivers
- type 1 is built for production workloads, type 2 for test setups and a developer's workstation
The Proxmox VE platform, covered in detail in the article what is Proxmox VE, is an example of an open-source type 1 hypervisor.
Comparing hypervisors by key parameters
Choosing a hypervisor type usually comes down to one question: is the server dedicated entirely to virtualization, or does it share resources with other tasks.
| Parameter | Type 1 (bare-metal) | Type 2 (hosted) |
|---|---|---|
| Where it runs | directly on the server hardware | on top of the host operating system |
| Access to CPU and memory | direct, without an intermediary | through the host OS kernel |
| Typical use | production servers, data centers | a developer workstation, a test setup |
| Examples | Proxmox VE, VMware ESXi, Microsoft Hyper-V in server mode | VirtualBox, VMware Workstation, Parallels Desktop |
On a dedicated server with a type 1 hypervisor, processor virtualization is used more fully — details are covered in the article virtualization on a dedicated server.
How the processor supports virtualization
Both hypervisor types rely on hardware processor extensions — Intel VT-x or AMD-V. The extensions add a separate execution mode for guest systems, so a virtual machine cannot directly interfere with the host or neighboring machines. Checking whether virtualization support is enabled on a Linux server takes one command.
egrep -c '(vmx|svm)' /proc/cpuinfoA number above zero means the processor supports hardware virtualization and the kernel sees the corresponding flag. For a type 1 hypervisor this is a mandatory condition to start, for type 2 it is a requirement for an accelerated mode without software emulation.
What limits the choice in practice
A type 1 hypervisor needs a dedicated physical server or a dedicated disk partition for installation — it does not coexist with a full desktop operating system. In exchange it provides access to live migration, clustering, and fine-grained control over how resources are split among dozens of virtual machines at once.
A type 2 hypervisor is easier to deploy on top of an existing installation, but the host OS overhead takes a share of the processor and memory, and virtual machine density on one server ends up noticeably lower. The difference between a ready virtual machine and an LXC container is covered in the article LXC or a virtual machine in Proxmox.
What to do when choosing a hypervisor
The decision is easier to make step by step rather than by intuition.
- determine whether the server is dedicated entirely to virtualization or shares resources with other tasks
- check hardware virtualization support with the command from the previous section
- estimate the expected number of virtual machines and their combined load on the processor and memory
- pick a type 1 hypervisor for production workloads, and type 2 on a workstation for occasional tests
Once the platform is chosen, it is worth planning backups and monitoring right away — doing this at install time is easier than adding it later.
Frequently asked questions
Is Proxmox a type 1 or type 2 hypervisor?
Proxmox VE is a type 1 hypervisor: it installs directly on the physical server and itself acts as the operating system for managing virtual machines, with no intermediate host OS.
Can a type 1 hypervisor run on a regular home computer?
Technically yes, if the processor supports hardware virtualization, but the home computer then stops being a regular workstation — the whole disk and all its resources go to the hypervisor.
Why does a type 2 hypervisor run slower than type 1?
Because every request a virtual machine makes to the processor or disk passes through the host operating system's scheduler instead of reaching the hardware directly, the way a type 1 hypervisor does.