Memory Usage stats different from Guest OS stats

[MightySlaytanic]

Hi,
I have some Ubuntu 22.04 VMs with qemu-guest agent installed and I've notice that the memory usage shown in the GUI is completely different from memory stats within the Ubuntu guest OS. Is it a problem of the guest agent? Does it computes memory usage as (used+buff/cache)/total instead of used/total?

# pveversion
pve-manager/7.3-3/c3928077 (running kernel: 5.15.74-1-pve)

 

[Dunuin]

From the hypervisor's point of view everything that isn't "free" is "used". So buff+cache counts as "used" as it indeed uses up the physical memory (at least for Linux). For Win VMs with guest agent it shows "cache" as "free". For FreeBSD it will just show the memory footprint of the KVM process.

 

[MightySlaytanic]

From the hypervisor's point of view everything that isn't "free" is "used". So buff+cache counts as "used" as it indeed uses up the physical memory (at least for Linux). For Win VMs with guest agent it shows "cache" as "free". For FreeBSD it will just show the memory footprint of the KVM process.

Thank you very much for explaining