A bit of context first : on Windows 2008 Standard x64 with 8Gb RAM, I have 5 VMs running which should take up 1664Mb RAM (3*256Mb+384Mb+512Mb). There is nothing else running on this server except the basic OS components (this not a Core installation). I know that each VM will use more RAM on the host than what has been configured in Hyper-V.
But when I run the task manager, it says 6.7Gb used ! If I sum up the RAM used by each process in the task manager (showing all users processes), I get to something around 1Gb...
So : how can I check how much RAM each VM is really using on the host (it does not seem to be available via task manager) ?
Note that I am aware of the fact that my problem could be unrelated to VM RAM usage, but I would still very much like to know how to do this.
Have you considered using the trial versions of either SCVMM or Hyper9 to manage your Hyper-V environment, at least temporarily. It sounds like you need to invest in a management tool for your virtual infrastructure.
I think with Performance Counters you can see that.
Look at https://docs.microsoft.com/en-us/archive/blogs/tvoellm/monitoring-hyper-v-performance which has a section
I don't have a Hyper-V machine handy to make sure it works, but take a look at Sysinternal's VMMap (http://technet.microsoft.com/en-us/sysinternals/dd535533.aspx)
From the description: