Memory ballooning: Should ubuntu guest reports a change in total ram?


Jul 4, 2019
With PVE 6.4-6 and ubuntu 20.04.2 as guest VM, I am trying to use memory ballooning.
The system has 64 GB RAM and at the moment only 3 OS are running, 2 are using in total < 2 GB RAM, so most RAM is available for the ubuntu VM.

I set the VM to have 8 GB minimum, and 48 GB as memory, with the ballooning box checked.

Problem is, it appears that within the ubuntu guest, I somehow see RAM reported as 7.01 GB:

With Swap also full. It does not seem like the VM was able to claim more memory from the host.
From the webGUI, the guest however seems to have claimed the memory:

But for some reason only 6.75 GB is utilized.

Is there something I missed in the configuration?


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