A guest operating system (guest OS) is the operating system running inside a virtual machine (VM), alongside the applications installed in that VM. Virtualization software provides the virtual hardware on which it runs.
What is a guest operating system?
The guest OS is the operating system component of a VM’s software stack. The U.S. National Institute of Standards and Technology (NIST) describes it as the OS running an instance with its applications, as well as the operating-system layer alongside virtual hardware, middleware, and applications. Oracle’s VirtualBox User Manual puts it simply: “This is the OS that is running inside the virtual machine.”
| # | Preview | Product | Price | |
|---|---|---|---|---|
| 1 |
|
Operating Systems: Three Easy Pieces | $28.27 | Buy on Amazon |
| 2 |
|
Operating System Concepts | $92.15 | Buy on Amazon |
| 3 |
|
Modern Operating Systems (4th Edition) | $221.00 | Buy on Amazon |
| 4 |
|
Operating System Concepts | $157.69 | Buy on Amazon |
| 5 |
|
Operating Systems: Principles and Practice | $60.96 | Buy on Amazon |
As an Amazon Associate I earn from qualifying purchases.
For example, a computer can run one OS directly while a VM on that computer runs another OS as its guest. The guest does not have to match the host’s OS family, but whether a particular guest is supported or optimized depends on the virtualization product.
What is the difference between a guest OS and a host OS?
The guest OS runs inside a VM. In hosted virtualization, the host OS runs on the physical computer, and the hypervisor runs on top of that host OS. The hypervisor manages the guest OS and mediates its access to the computer’s physical hardware.
#1 Best Overall
These terms describe different layers, not interchangeable names: the VM is the virtual environment; the guest OS is the operating system running in it. NIST’s host-OS definition is specifically about hosted virtualization, so the host-OS layer should not be assumed to exist in the same form in every virtualization architecture.
What does the hypervisor do?
A hypervisor is the virtualization component that manages virtual machines and controls instruction flow between guest operating systems and physical hardware. It presents virtual hardware to a guest, allowing the guest OS and its applications to run in the VM rather than directly on the physical machine.
Rank #2
Which operating systems can run as guest OSs?
That depends on the virtualization product and its version. For example, Microsoft’s Hyper-V documentation covers supported Windows Server, Windows, and Linux guest operating systems, and links to support information for FreeBSD. Compatibility can depend on the host and guest versions, VM generation, and integration services; consult Microsoft’s supported Windows guest operating systems for Hyper-V documentation for the applicable combination.
When selecting a guest OS, check the product’s compatibility information for the guest version and edition, host or hypervisor version, VM generation or architecture, virtual processor and memory limits, required integration tools or drivers, and support provider. Microsoft says it supports issues in its own operating systems and integration services; certified third-party operating systems are supported by their vendors.
Quick Recap
Best Value
Rank #4
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
