Linux VM doesn't show given memory

[TrickyTrix]

I have Proxmox 9.1 with 64 GB of RAM and zfs filesystem, and 73.3% of memory is currently in use.
I created Linux VM (named Docker) with minimum of 4GB and maximum of 16GB of RAM (47.20% is currently in use).
The thing is, when I ssh in to the VM and run htop, free -h and cat /proc/meminfo I dont see more than 8GB of RAM.
What am I doing wrong?

 

[Impact]

With ballooning the memory is usually given slowly and on demand. With PCI(e) passthrough ballooning doesn't really work though. Can you share the node's Summary too?

 

[SteveITS]

Presumably you have ballooning enabled on the VMs if you are setting min/max. Is (was) the host over 80% RAM usage? If so then it will remove memory from the VMs as directed.

 

[beisser]

you are using pcie passthrough.
minimum and maximum memory doesnt make sense there as the host reserves the full 16gb anyway (see host memory usage on your screenshot).
what happens if you set min and max both to 16gb?

 

[TrickyTrix]

you are using pcie passthrough.
minimum and maximum memory doesnt make sense there as the host reserves the full 16gb anyway (see host memory usage on your screenshot).
what happens if you set min and max both to 16gb?

I have GPU passthrough and didn't know that all given memory is fully taken from host when passthrough is used.
When I set minimum memory same as maximum, host memory usage stays almost the same and VM sees 16GB as max memory instead of 8GB, so it makes sense that all given memory is fully taken from host, but question remains why VM doesn't see maximum given memory when minimum memory is set differently from maximum memory.

Btw how can I see how much memory ZFS consumes on the host?

 

[beisser]

there is a stat in the graph called zfs arc with its own color. that shows how much is used for zfs.

 

[TrickyTrix]

Thank you for all useful info, I learned a lot.