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

You can specify an existing zfs dataset in lxd init, without a dedicated partition… I typically create a single zpool with the biggest partition of the disk, then create an “lxd” zfs dataset in that zpool and use it as the LXD default storage. I also have other zfs datasets in the same zpool, so they share the same partition with LXD.