100% VM CPU in ESX Performance Tab but Task Manager Shows None
Yesterday, I tried the cpuid.coresPerSocket setting on a testing W2K3 Web Edition VM (plain install, no SP), I set cpuid.coresPerSocket = 4 with 8 vCPUs and I was able to boost the VM to 8 CPUs in task manager (ie, 2 sockets with 4 cores on each sockets), then I remove the cpuid.coresPerSocket parameter from .vmx and reduce the vCPU to 1, problem started to occur after reboot the VM.
Veeam Monitor and ESX Performance Tab started to show CPU over usage alarm and CPU stayed at 100% no matter what, I even remove the VM from Inventory as added it back again as I though it may solved the problem, nothing worked until I found VMware KB1077.
However there is no option in Device Manager > Upgrade Computer HAL to change from Multiprocess HAL to Uniprocessor HAL prior W2K3 SP2, I do have a little program to do it, but I forgot where I put it, so I simply upgrade the VM to SP2 and all the problem disappear after reboot.
I don’t think this will occur in W2K8, probably only happen in old OS like W2K, W2K3 prior SP2, so all you need to do is to select the correct processor HAL for your VM.
