Redundancy and Backups

Redundancy takes different forms at each layer. Power can be duplicated with devices that have two power supplies fed from separate circuits, so that the loss of one feed does not stop the equipment. Dante offers a redundant mode in which the primary and secondary ports send the same audio over two networks; Audinate requires the two networks to be separate and never interconnected, and when one fails the audio continues on the other without interruption. Consoles, media servers and clock sources can have a backup unit. Terms vary between manufacturers, but a cold or warm spare generally needs a manual switch-over with a short interruption, while a hot or mirrored backup follows the main unit and takes over automatically.

Show files are the cheapest protection. The lighting console show, the media server content and cue list, and the mixing console scene file are copied to a second medium and kept current, so that a failed device can be replaced and reloaded instead of reprogrammed from memory. For data backups in general, the US agency CISA recommends the 3-2-1 rule: three copies, on two types of media, with one copy off site.