Hey everyone,

Apologies upfront. The description I gave for Minroot and when to use it all apply, but the way to implement via PowerShell was incorrect. Configuring Minroot is a simple bcdedit command which works today on Windows Server 2022/2025. A restart is required for this change to take effect.

Here's an example:
If you have a server with 32C/64T and wanted to conservatively set Minroot to use 50% of the cores in the system, the bcdedit command is:

bcdedit /set hypervisorrootproc 32

Keep in mind that hypervisorrootproc is setting the number of virtual processors that the root partition can use for servicing I/O. If I wanted to be more aggressive, and limit the root partition to 25% of the cores in the system, the bcdedit command is:

bcdedit /set hypervisorrootproc 16

As I said in the session, Minroot isn't a general-purpose feature that you should configure on every server. For most scenarios, you don't need to alter Minroot, just let Hyper-V automatically manage CPU usage. However, for those edge cases where VM jitter must be kept to an absolute minimum (manufacturing is where we've seen this most), Minroot can be impactful. Thanks everyone!