How to exceed the 4 vCPU limit for VM’s on Hyper-V
Many times I was asked for the way to exceed the limitation of 4 virtual processors assigned to a virtual machine for Windows Server 2008 R2.
I guess there is still many Windows Server 2008 R2. hypervisor running on a physical server which has much more cores in your data-center.
Although It is very limiting, but I will not recommend you to modify VM’s setting on a productions servers to exceed the limit.
I will show you the steps, you can try it on your responsibility
1- Copy the virtual machine configurations file, it’s a .xml file stored in the virtual machine folder.
Search for “processors” section. Then change the ‘count’ parameter
Note: ‘count’ number cannot exceed the number of cores of the host machine.
In this example I changed count from 4 to 8
Then save the file, pay special attention to save it in xml format
3- overwrite the original configurations file, check the VM’s state and make sure is off before overwriting the configurations file.
4- check the Number of logical processors from the VM settings, it should match the entered value in configuration file.