Has there ever been any reason to look into the Hyper-V balloon driver and its effects on memory?
This is the RAMMap readout for an idle Hyper-V guest. Task Manager shows 1.7 of 2 GB of RAM in use, but there’s effectively nothing running — the Hyper-V balloon driver has claimed most of the pages, which are now under “Driver Locked”:
There’s likely nothing that can be done with Task Manager which will always misreport the memory, but it would be nice if Nagios would not waste anyone’s time reporting non-existent memory shortages.
Unfortunately there’s seemingly no official way for any guest software to see what’s going on, but since Driver Locked is likely to remain low (820 kB on another Hyper-V guest on the same architecture) then it could be argued that NSClient++ could subtract the Driver Locked figure from memory usage to try to approach a more readable figure.
Alternatively, maybe there is a better workaround.