Only 'online' data is live/surviving data... So I keep a raid5 array of (currently 4) disks running for my storage needs. This array has been migrated over the years from 4x1 TB, to 2TB, to 4TB, 8TB and now 4x 16TB disks. The raid array is tested monthly (automated). I do make (occasional, manual) offline backups to external HDD's ( a stack of 4/5 TB seagate 2.5" externals), but this is mostly to protect myself from accidental deletions, and not against bitrot/failing drives.
Tapes are way to slow/expensive for this (low) scale, optical drives are way to limited in capacity, topping out at 25/50GB, and then way to expensive to scale.
Tapes are way to slow/expensive for this (low) scale, optical drives are way to limited in capacity, topping out at 25/50GB, and then way to expensive to scale.