EntityQ1630659· pop 6· linked from 24 articleshot spareSign in to savespare component that is an active and connected part of a working system, ready to take over functionality with little or no interruptionConnectionscomputerEntityhard diskEntityprinterEntityelectrical generatorEntityvacuum tubeEntityRAIDEntityhot swappingEntitycoal-fired power stationEntitydatabase serverEntityhigh availabilityEntityfailoverEntitydata lossEntityhot cathodeEntitymean time to recoveryEntityCategoriesFault-tolerant computer systemsRAIDReliability engineering