Node Memory Usage Broken? Reports VM as Always Using Entire Allocated Memory.

[jedi0318]

I currently have an Ubuntu and a Windows 11 VM running on my Promox node. The node has 24gb of RAM, and I have allocated 12gb to the Windows VM. I set up ballooning on both Proxmox and inside the VM, and the reported memory usage in the VM Summary matches Windows Task Manager as expected. However, when looking at my Node RAM usage, it appears to think that the Windows 11 VM is using all 12gb of memory. Increasing the Windows VM to 16gb makes the Node usage shoot up the same amount, and turning off the Windows VM instantly drops the Node usage to the same as the Ubuntu machine's usage. How do I fix this? The Ubuntu machine is a Minecraft server and I want to make sure it can access its allocated memory when needed.

VMs:

Windows 11 -


Ubuntu -

Node:

 

[LnxBil]

This is normal and asked at least once a week. It's cache and that windows is lying to you because it declares cached memory as free and it created the illusion that this is normal, which is not. Only used RAM is good. Keep also in mind that ballooning only kicks in if you are under memory pressure and states, that a VM will volunteer memory to others and does not mean that is has minimum and will grow.

 

[jedi0318]

This is normal and asked at least once a week. It's cache and that windows is lying to you because it declares cached memory as free and it created the illusion that this is normal, which is not. Only used RAM is good. Keep also in mind that ballooning only kicks in if you are under memory pressure and states, that a VM will volunteer memory to others and does not mean that is has minimum and will grow.

So if my Minecraft server starts asking for 10gb of RAM, will RAM automatically be given up and reallocated from the Windows VM?

 

[LnxBil]

So if my Minecraft server starts asking for 10gb of RAM, will RAM automatically be given up and reallocated from the Windows VM

Further information can be found here.

 

[Dunuin]

So if my Minecraft server starts asking for 10gb of RAM, will RAM automatically be given up and reallocated from the Windows VM?

No. The sum of RAM of all VMs should be less than the amout of RAM your host got. And you want some free RAM for PVE itself, for the virtualization overhead, caching and some reserve to not OOM. So with 24GB of RAM I wouldn't assign VMs/LXCs more than a sum of 18-20GB.
You usually don't want to overprovision RAM. So if you assign 12GB to a windows VM and 10GB to a Minecraft VM, count those 22GB as lost, no matter what the VMs are reporting. Its also probably more like 24GB and not 22GB because of the overhead of the KVM process.

 

[LnxBil]

No. The sum of RAM of all VMs should be less than the amout of RAM your host got. And you want some free RAM for PVE itself, for the virtualization overhead, caching and some reserve to not OOM. So with 24GB of RAM I wouldn't assign VMs/LXCs more than a sum of 18-20GB.
You usually don't want to overprovision RAM. So if you assign 12GB to a windows VM and 10GB to a Minecraft VM, count those 22GB as lost, no matter what the VMs are reporting. Its also probably more like 24GB and not 22GB because of the overhead of the KVM process.

We need a dedicated Wiki page for this that we can just reference ...