The bottom line is you have to dispense with the fantasy that any media will reliably
keep data for really any length of time. You must habe resundancy. You could go the
optical route, but even witj redundancy I don't recommend it. If it's a small
amount of data, maybe it's not such a bad idea, you can have 3 or more copies. But
backing up a lot of stuff will be very laborious. And likely won't save money as
compared to magnetic disks.
I'm done with the sargasso sea of cables. I bought 2 3tb 2.5" usb drives (and all
my data may be bigger then 4tb). I'm scaling down everything.