Not only that but that redundancy is hidden from everything. Already decades ago the Hungarian electricity distributor had a "RAID" storage unit where one bunch of disks were at the capitol, the other bunch connected with fiber at another city -- and you talked to this thing as if it were an ordinary disk. Short of an invading army nothing could cause data loss on that thing -- simple aerial bombing wouldn't because the unit in the capitol was tens of meters underground... that's not concerns you have on your average web app.