What happens in a stack if multiple services use the same named volume?

Hello,

in a scenario where there is no replication of the volumes across the hosts, what happens when the some service in a stack use the same named volume? The allocation of the containers on the varioous hosts will be constrained like when using --volumes-from so that the containers using the same volumes will be allocated in the same host or there is no constraint, i.e. producing a container X on host A which us using the volume “foo” and a container Y on host B using a volume with the same name “foo” but with different data?

Without some kind of storage solution, there is no constraint, you would produce a container X on host A which us using the volume “foo” and a container Y on host B using a volume with the same name “foo” but with different data?