I have a Server 2008 R2 Enterprise server running HyperV (Host)
There are 2 VMs on the server
My Host server has 16gigs of RAM installed. Task Manager shows that memory usuage is at 91% but list very few things running and none of which are using a lot of memory.
I ran Sysinternals RamMap and found that 8 gigs of memory is under "Driver Locked" which is exactly correct since each VM has 4 Gigs but then I discovered that 7gigs of is also listed under "Mapped File". When I viewed File Summary , it shows that the file is the VHD for the "data" drive to one of my VMs. I chose the option to empty standby list but nothing has changed. I have no clue why this one VHD would show as a mapped drive. I have other Hyper V servers and I do not see this behavior on them but they are in a cluster using CSV so its not a direct comparison.