fully redundant
Computing term describing a system or component that has complete duplication for fault tolerance.
This system has a fully redundant configuration.
冗長 means 'redundant' in general, while 完全冗長 specifies full redundancy, often in fault-tolerant systems.
fully redundant system
Compound of 完全 (complete) and 冗長 (redundant). The exact derivation is uncertain; the spelling is conventionally associated with the meaning.