Steps to create error:
take a snapshot of a container running on server1: lxc snapshot foo foo200525
copy the snapshotted container from server1 to server2: lxc copy server1:foo/foo200525 foo
do some stuff with the copied container on server2
try to snapshot the copied container on server2: lxc snapshot foo foo200525
Error: Create instance snapshot: Failed to run: zfs snapshot tank/lxd/containers/foo@snapshot-foo200525: cannot create snapshot ‘tank/lxd/containers/foo@snapshot-foo200525’: dataset already exists
This error occurs when using the same snapshot name as on server1 which indicates that the snapshot on server1 follows on to server2 even if there are no snapshots of foo currently on server2
Solved by using another snapshot name, but as there are no snapshots of foo on server2, why get an error?