Buffalo HS-D300GL User Manual page 5

4. Disk Full LED – When LinkStation's internal
drive approaches 95% of its capacity, the
Disk Full LED will light up in red. For
options to increase storage capacity, see
LinkStation Expansion on page 26.
5. Diagnostic LED – The Diagnostic LED
flashes if the LinkStation encounters an
error.
6. USB Port (Front & Rear) – LinkStation
offers two USB Ports for adding external
drives or USB printers. Please see the
LinkStation Expansion section on page 26
to learn more about how to take advantage
of the USB Ports on LinkStation.

LinkStation Diagram