[SOLVED] Memory used - where is truth

[Morphushka]

Hello. I have VM with debian and 10Gb memory for this machine.
Proxmox GUI says 7.8Gb used

Inside vm htop says 1.42Gb used


What shoud I think on it ?
Thanks!

 

[t.lamprecht]

But do you see the big orange chunk of the bar in htop? That's probably the remaining "usage".
You could call free -h in the VM to see that too, listed under "buff/cache".

The issue with that kind of memory usage is that the VM itself doesn't accounts this as "reserved", as it's the page cache, and can be reclaimed at any moment (it's just optimal use of the available memory for disk IO caching, as unused memory is wasted memory). But Proxmox VE on the outside does not see the difference, either a memory page is in use by the VM or not, it doesn't knows what the VM Guest OS is doing with that memory exactly,

Normally, what helps is to ensure that the "Ballooning Device" is enabled for the VM, as it helps to improve tracking memory with the help of the Guest OS:

 

[Morphushka]

Thanks you very much! Now it's clear to understand.