Hyper-V - Wikipedia
https://en.wikipedia.org/wiki/Hyper-V
Microsoft Hyper-V, codenamed Viridian, and briefly known before its release as Windows Server Virtualization, is a native hypervisor; it can create virtual machines on x86-64 systems running Windows. Starting with Windows 8...
Hyper-V Blog
https://www.hyper-v.io/
Rebooting the Hyper-V server is a necessary course of action. Hyper-V Replica will help you to develop one more reliable strategy to protect your infrastructure!