Your write up is pretty good To me the "2 media" It is not strictly 2 media, ie hdd and dvd. Or hdd and tape. It is primarily to ensure you are on 2 devices/s

Your write up is pretty good To me the "2 media" It is not strictly 2 media, ie hdd and dvd. Or hdd and tape. It is primarily to ensure you are on 2 devices/systems/ etc For individuals the could be their local system and a home nas On reason this was created is that in enterprise most systems are backed by a SAN. Having your prod data AND backup data on the same physical storage device or cluster would violate the rule. Often times admins miss this because the storage layer is cluster and partitioned in away that could give the appearance of it being separate even if physically it is the same device Further cloud storage can count has separate media as well So if you have the prod copy of data + a backup on a local nas + copy on backblaze or another cloud storage provider you have followed the 3-2-1 rule