How to set the container to can use the maximum resources of the physical machine

You could have read the sentence directly under it:

Because I for example have a btrfs and a zfs storage pool on my ext4 harddrive, created by LXD.

I did. I didn’t answer because I didn’t have anything new to add to what I have already written.

Your btrfs and zfs storage pools on your ext4 partition are obviously simulated filesystems. If you like them, enjoy. I also used them for learning how zfs works. I now prefer using a zfs filesystem on a raw partition, as I said before.

Interesting :thinking:.
Didn’t know there is a difference.

Anyway this seems to be one more reason LXD should be able to create a simulated filesystem on a second harddrive or partition.
Maybe someone can check that, so we finally would have an answer.