Virtualization: Part 7 — Hyper-V

Hyper-V is Microsoft’s hypervisor. It is included in Windows Server as a role and in Windows 10 and 11 Pro and Enterprise editions as an optional component. Hyper-V is a Type-1 hypervisor: once the role is enabled it boots before Windows, and Windows itself continues to run as a privileged partition from which the other machines are managed.

Hyper-V is a natural choice if a company’s infrastructure is built on Windows: Active Directory, file servers, 1C on Windows, terminal servers.

How much it costs

There is no separate charge for Hyper-V, but you have to pay for Windows Server.

• There is no free Hyper-V Server anymore. The last free version was Microsoft Hyper-V Server 2019, whose extended support ends on January 9, 2029. In Windows Server 2022 and 2025 Hyper-V is available only as a role of the licensed system.
• Windows Server licensing is by physical host cores: all cores must be licensed, at least 8 per processor and 16 per server.
• Standard — when all cores are licensed, allows you to run two virtual machines with Windows Server. For more machines, licenses are purchased again for all cores.
• Datacenter allows an unlimited number of Windows Server virtual machines on a fully licensed host. It is chosen when there are many Windows virtual machines.
• Guest Linux systems do not require Windows licenses.

For Russian companies note that in March 2022 Microsoft suspended new sales in Russia, so it is not possible to purchase new licenses directly. This is an important argument when choosing a platform for new projects.

Capabilities

• Hyper-V Manager and PowerShell. A graphical console for individual hosts and a full set of PowerShell commands for automation (New-VM, Start-VM, Checkpoint-VM, and others).
• Windows Admin Center — a web console for managing servers and Hyper-V clusters from a browser.
• Live migration — moving a running VM between hosts without stopping it, including without shared storage.
• Failover Clustering: when a host fails, its VMs are restarted on other nodes. A cluster requires shared storage or Storage Spaces Direct in the Datacenter edition.
• Hyper-V Replica — asynchronous copying of VMs to another host or site with the ability to fail over to the copy in case of an incident.
• Checkpoints (snapshots) — standard and “production”, which use in-guest backup mechanisms and are safer for database servers.
• System Center Virtual Machine Manager — a paid product for managing large installations.

Shielded VMs and the Host Guardian Service, which were previously presented as advantages of Hyper-V, have been marked deprecated by Microsoft starting with Windows Server 2022 — you should not build new solutions on them.

How to enable Hyper-V

On Windows Server the role is installed with a single PowerShell command run as administrator:

Install-WindowsFeature -Name Hyper-V -IncludeManagementTools -Restart

On Windows 10 and 11 Pro or Enterprise:

Enable-WindowsOptionalFeature -Online -FeatureName Microsoft-Hyper-V -All

Requirements: a 64-bit processor with SLAT and hardware virtualization support, at least 4 GB of RAM. Hyper-V cannot be installed in Home editions of Windows.

After enabling Hyper-V, other virtualization programs that directly use the same CPU capabilities (VMware Workstation, VirtualBox) may work unstably — Microsoft warns about this in the documentation.

Guest Linux systems

Modern Linux distributions include Hyper-V drivers in the kernel and work without additional installations. For Linux use generation 2 VMs (UEFI); with Secure Boot enabled, choose the “Microsoft UEFI Certificate Authority” template for Linux, otherwise the system will not boot.

When to choose Hyper-V

• The infrastructure already runs on Windows Server, Datacenter licenses are purchased, and administrators know PowerShell.
• A cluster and replicas are needed, and there are no specialists in Linux virtualization.
• There are many Windows virtual machines, and a Datacenter license for the host is more economical than individual licenses.

If you don’t have Windows Server licenses and it’s difficult to buy new ones, and guest systems are mostly Linux, it makes more sense to consider Proxmox VE: it is free and does not require host licenses. If Windows Server is needed in the cloud, it can be deployed with a Russian provider — there is an example in the article “Installing Windows Server in Yandex.Cloud”, and we provide turnkey installation as a service.

Common mistakes

• Unlicensed cores: fewer Standard licenses bought than the host cores, or more than two Windows Server VMs are running per Standard license.
• Checkpoints instead of backups: a chain of snapshots grows, slowing the disk and not protecting against storage failure.
• Dynamic memory for database servers and 1C without taking application requirements into account: the server gets less memory than it needs under load.
• Cluster without validation: before putting into production run the cluster validation (Test-Cluster) and fix warnings about network and storage.