I’m assuming you’re using ZFS, LVM or CEPH, in which case the /var/lib/lxd/storage-pools/POOL/snapshots will always be empty as the snapshots don’t appear as filesystem objects.
/var/lib/lxd/snapshot is used when a snapshot is mounted, which it very rarely is. This gets temporarily used during lxc snapshot, lxc publish and some lxc file operations against a snapshot.
Yeah, you have a storage pool and that storage pool doesn’t mount the snapshots, so what you’re getting is perfectly normal.
You can make snapshots, restore them, create containers from them, … Not having them be visible on the filesystem doesn’t prevent any of that and users are usually not expected to go poke at those things directly anyway.
in the end i did this while the containers were running and is mount on the filesystem and i manually copied it and recreate the same in other machine despite all thanks i am so sorry if my stupid knowledge is that bad have a great day i wish you all the best.