This is where glusterfs expects them; see also https://github.com/gluster/glusterfs/blob/v3.10.1/extras/hook-scripts/Makefile.am#L4 Also see upstream bug https://bugzilla.redhat.com/show_bug.cgi?id=1452761
This service is only limited in configuration options. But it is sufficient to run glusterd and configure it using the gluster command