  We present a slow control system to gather all relevant environment
information necessary to effectively and reliably run an HPC (High Performance
Computing) system at a high value over price ratio. The scalable and reliable
overall concept is presented as well as a newly developed hardware device for
sensor read out. This device incorporates a Raspberry Pi, an Arduino and PoE
(Power over Ethernet) functionality in a compact form factor. The system is in
use at the 2 PFLOPS cluster of the Johannes Gutenberg-University and
Helmholtz-Institute in Mainz.
