Am I mis-reading this memory usage on the summary page?

[survivalbloke]

I've got Proxmox VE running bare metal on a machine with an i7 9700k and 32GB DDR4 memory. I've created two VM's. One of them is an Ubuntu headless server running a few docker containers and doing nothing else. The second is pfSense which is my firewall. I noticed the reported memory consumption of pfSense was 6.75GB of the allocated 8GB which seems crazy because according to the people at netgate, even 4GB of RAM is more than enough. The Ubuntu machine shows nearly 19GB of the 20 allocated. This just can't be accurate. What am I missing?

pfSense (imgur)

Ubuntu server (imgur)

 

[leesteken]

Install qemu-guest-agent inside the Ubuntu VM, set Options > QEMU Guest Agent to Enabled and enable the Ballooning device in Hardware > Memory settings (and restart the VM). Both these things will improve the reports about the VM, even when you don't actually use ballooning (by decreasing the Minimum memory setting).
I don't know if pfSense has a QEMU guest agent and you might have to enable the balloon device driver manually in the underlying BSD.

EDIT: The filesystem cache inside the VMs is usually not counted/reported inside the VM (because it can be freed/reused at any time) but the Proxmox host does not know which part of the actual used memory is cache and therefore always reports higher memory usage.

 

[Dunuin]

Install qemu-guest-agent inside the Ubuntu VM, set Options > QEMU Guest Agent to Enabled and enable the Ballooning device in Hardware > Memory settings (and restart the VM). Both these things will improve the reports about the VM, even when you don't actually use ballooning (by decreasing the Minimum memory setting).
I don't know if pfSense has a QEMU guest agent and you might have to enable the balloon device driver manually in the underlying BSD.

OPNsense just got a qemu-guest-agent plugin. But that plugin is not fully compatible and if I remember right it won't support ballooning. It's basically only useful to see the IPs from the Proxmox WebUI. And that plugin was made by the OPnsense community. As far as I know there is no official OpenBSD qemu guest agent.
For OPNsense PVE will basically only look how much RAM your KVM process running OPNsense is using. And KVM will consume nearly all RAM you assign no matter how much of that RAM the guest is actually using. I think that should be the same for pfsense. So if you don't want PVE to waste RAM, you shouldn't give that VM more RAM than it actually really needs.

 

[survivalbloke]

Install qemu-guest-agent inside the Ubuntu VM, set Options > QEMU Guest Agent to Enabled and enable the Ballooning device in Hardware > Memory settings (and restart the VM). Both these things will improve the reports about the VM, even when you don't actually use ballooning (by decreasing the Minimum memory setting).
I don't know if pfSense has a QEMU guest agent and you might have to enable the balloon device driver manually in the underlying BSD.

EDIT: The filesystem cache inside the VMs is usually not counted/reported inside the VM (because it can be freed/reused at any time) but the Proxmox host does not know which part of the actual used memory is cache and therefore always reports higher memory usage.

This worked a charm! I'm digging around for a working port of the guest agent for BSD. I can just log into the VM itself and monitor usage but I like to have it all under a nice pretty interface. Thanks again!

 

[survivalbloke]

OPNsense just got a qemu-guest-agent plugin. But that plugin is not fully compatible and if I remember right it won't support ballooning. It's basically only useful to see the IPs from the Proxmox WebUI. And that plugin was made by the OPnsense community. As far as I know there is no official OpenBSD qemu guest agent.
For OPNsense PVE will basically only look how much RAM your KVM process running OPNsense is using. And KVM will consume nearly all RAM you assign no matter how much of that RAM the guest is actually using. I think that should be the same for pfsense. So if you don't want PVE to waste RAM, you shouldn't give that VM more RAM than it actually really needs.

Yeah I learned there's no official package for FreeBSD. I did find someone who ported it in, and apparently it worked, but there's an issue with their makefile and it won't compile, so oh well.