For most installations, a standard 19" equipment rack is used to securely and cleanly install most all of the electronics gear.
For these installations, Allonis recommends the myServer 6 1U Rack mount package.
As the name implies it takes up a 1U (1 1/2") vertical space in the rack.
Up to 4 Raspberry Pi controllers can be mounted. Blank plates are optionally available to fill the unused holes.
So, one of the Pi's can be the primary myServer 6 controller. For robust and critical installation, a secondary myServer 6 controller can be used as an automatic system backup.
PIs can be used as myMediaPlayers. Or Digital Signage players. Or myAudioPlayers. Or IO devices. The list is long of services that the Allonis suite of products covers.
For the PIs, common is to use a GPIO fan to cool the processor. This is a critical component as without, the CPU will certainly overheat which will cause poor system performance and can be damaged permanently. Thankfully they are inexpensive and readily available to replace. Simply gracefully shut down the Operating System, unplug the PI's power supply and carefully remove the fan from it's GPIO pins. Replace it in reverse being careful to ensure all GPIO pins are aligned before pressing together. Power up the Pi to restore the system.
For installation, it is important for the equipment rack to be in a ventilated area with cool flowing air. Fans are available for equipment racks. The myServer 6 is happiest in the lower areas as heat rises. Ensure there is space around the Controller.
The myServer 6 controller (and all other PIs) should be connected to a UPS to ensure stable power even in the event of a power outage or brownout.
Shelf mount myServer 6 controllers are also available for smaller systems.