Windows 2012 std host with Hyper-V. Hyper-V guest VM is Windows server 2019 std
Both the host and the VM are setup as separate SQL & IIS application platforms with some light add-on tools such as FTP server, and backup agent.
Today, without any changes to either Host or VM since the last Windows update on the VM 18th March 2021 (posting this on the 25th March 2021) the VM exhibits near 100% CPU usage from seemingly lightweight processes such as task manager! (see pic)
The VM and Host are so slow I've had to emergency failover to warm standby machines.
Previously this problem had occurred with with the VM running Windows 2016 std. We thought because the issue came and went randomly it was a Windows update issue and replaced and re-created a brand new VM, new VHDX files with the current 2019 OS.
Attempts so far
reboots of both the VM and Host or just the VM have no effect
Stopping services such as SQL do lower the CPU usage percentage, but do not improve the responsiveness of the system performance, the UI or it's ability to serve IIS pages.
Stopping the Windows Update service has no real effect either.
Process monitor gives no real enhanced view of what is causing the high usage and slow performance.
What else can I try?
joeqwerty aligned my thinking, the machine is a mess and so we have simplified, migrated some load and removed the VM. Hopefully that will cause the issue of unusual load not to re-appear