guest Windows server 2025 - shows wrongly memory usage

[ZAJDAN]

Hi,
I am testing in PVE 8.3.0
host: 64GB RAM

guest with Windows server 2025.
RAM is set in this way:


When I look onto Memory usage in PVE of this guest:


guest itself show much less RAM usage:

 

[gfngfn256]

Search these forums on your topic & you will learn 2 basic things:

1. Even if the guest may show more available RAM than the HV shows, that does not mean the Guest is not using that RAM for caching etc.

2. Balooning is probably not exactly what you think it is.

 

[ZAJDAN]

Search these forums on your topic & you will learn 2 basic things:

1. Even if the guest may show more available RAM than the HV shows, that does not mean the Guest is not using that RAM for caching etc.

2. Balooning is probably not exactly what you think it is.

when I count Used+Cached = much less than PVE shows

 

[ZAJDAN]

I installed into the guest virtio drivers(balloning) and now it shows correctly

 

[gfngfn256]

when I count Used+Cached

Does not make a difference - guest is not "releasing" that RAM.

BTW, I assume you have installed GA/balloonservice in Windows.

 

[gfngfn256]

Just saw your added post. You will still see discrepancies in the future - as I have noted.

 

[_gabriel]

I installed into the guest virtio drivers(balloning) and now it shows correctly

it only help you to not over provision RAM for the VM.
32 GB is reserved and consumed from POV of PVE. No others guests or PVE itself can use the free ( cached neither not used) RAM of the Windows VM.