How to monitor RAM usage for Hyper-V VMs

First, you have to remember that in Hyper-V that the "host" is called a parent partition and it really just like a virtualized guest with special permissions and roles. Just like any other child/guest, when you open up Task Manager, you can not see the CPU usage of the other children on the server.

Ben Armstrong has a good explanation of this here: http://blogs.msdn.com/virtual_pc_guy/archive/2008/02/28/hyper-v-virtual-machine-cpu-usage-and-task-manager.aspx

To summarize his post, you need to check three things to get an accurate picture of CPU utilization:

1. View the CPU usage on each guest - this is available through Hyper-V Manager or Performance Monitor.

2. CPU usage due to context switching - this is the perfmon counter called % Hypervisor Run Time under Hyper-V Hypervisor Virtual Processor

3. Child partition worker process - vmwp.exe running on the parent partition (1 per child). This handles Hyper-V operations like saving state.

Windows will report all of the memory that is installed in the machine but how much it actually uses is dependent on the architecture: x86 or x64 and edition: Standard, Enterprise, etc. To allow Windows to use all 6GB you need to enable PAE but this is not applicable on Windows Server 2008 Standard Edition 32bit.

Here's an article that details how to enable PAE on Windows Server 2008, for your reference:

http://support.microsoft.com/kb/929580

And here's an article that details the memory limitations of various Windows Operating Systems:

http://msdn.microsoft.com/en-us/library/aa366778(v=vs.85).aspx#physical_memory_limits_windows_server_2008