<![CDATA[Reducing vCPU isn't done live on Windows]]>I'm doing a couple of tests to trying to figure out quirks and behaviours from XCP-ng side, for a future production (licensed) setup.

So I tried to see what would happen if I would play with the number of vCPUs on two guests.
TL;DR: Reducing vCPUs on Windows requires reboot.

On Windows Guest:
OS: Windows Server 25
Guest Agent: 9.2.385.0
Increasing the number of vCPUs up to the max value, is done live and works well. But reducing the vCPUs requires a reboot.

However. On a Rocky Linux 10 installation. The reducing works immediately live and online as expected.

This might very well be a limitation of how Windows does things internally. But I thought it interesting enouch to report about anyway.

]]>https://xcp-ng.org/forum/topic/12491/reducing-vcpu-isn-t-done-live-on-windowsRSS for NodeFri, 25 Sep 2026 08:06:52 GMTFri, 25 Sep 2026 06:24:52 GMT60