Incorrect RAM usage in webui for VM

[paulie420]

You need to wrap your head around the difference between "free" and "available". "free" is RAM that isn`t used at all. "Used" is RAM that is used in any way. "Available" RAM is RAM that is in use but could be quickly freed up by the guest OS when needed, so it is still kind of available.
What mosts Guest OSs will show is the "available" RAM and not the "free" RAM but you just interpet that as some kind of free. What PVE will show for Linux Guests with QEMU guest agent is "used" and "free" RAM. For Windows Guests with QEMU guest agent PVE will show "available" RAM. For OSs without a installed guest agent it will show the RAM usage of the KVM process as a fallback, as PVE can't query the RAM usage from the guest OS.
See for example: LinuxAteMyRAM.com

Thanks for the link - I do always install qemu-guest-agent, and tick the box one the PVE web GUI side, so that shutdown GUI works and the like... I'm understanding more - and I'm sure that displaying it this way helps sysops who are managing many PVE VMs - but for ME, I'd just like to see what the VM has available to IT... I'll read up on LinuxAteMyRAM.com - appreciate the message.

And ok - thank you even m0re... after reading the link above, even *I* am understanding whats going on w/ what PVE web GUI displays! ... I was able to run the drop cache command in my VM and see the memory 'shoot up' - I get it. We are giving that memory TO the VM and PVE web GUI is displaying what IT can give MORE to the VM...

Thanks again... I do wish I could display the 'available VM memory' - or... what newbies are worried about. But at least I understand why I always see this so high... it just means my VM HAS the memory it needs.