I'm testing CentOS 6.6 in Hyper-V (W2K12R2) with dynamic memory. I set Startup and Minimum Memory to 4096MB, Maximum Memory to 16384MB. 20% buffer size.
After boot I can see it's memory size as 3882MB from CentOS and memory demand is ~700MB in Hyper-V Manager on Host OS.
Than I tried to create couple of 2GB tmpfs mounts and filled them with random data. Since it was more than 4GB, memory size became to increase in guest OS and I saw memory size as 5996MB.
Than I erased everything from tmpfs directories and assigned memory on Host OS became 4096MB, demand memory 901MB. But memory size in CentOS stayed as 5996MB. Memory usage shown as 2940MB
Mem: 6140300k total, 3903940k used, 2236360k free, 116944k buffers Swap: 0k total, 0k used, 0k free, 775396k cached
1. Should guest OS see memory decrease?
2. If it shouldn't, how can I figure out real memory size and memory usage from guest OS?