[popo]

Of the source files, I keep them each on two hard disks. To me, there isn't another cost effective solution. DVDs, Blu-Ray, are all too small that I'd need an unmanageable number of them. Even with hard disks I need many TB worth, twice. To keep things simple, I just have two normal copies on different physical disks, not in the same computer. I don't use anything like raid 5 as that to me starts increasing risk once again.

 

I also kinda pre-emptively run around the risk of hard disks dying with old age. Since capacities continually increase, I tend to upgrade them every few years too. As backup disks don't get much power on time, they're less likely to die anyway. At some point I want to move to something like ZFS to prevent bit rot also, but to me the risk of that is low enough I'm not actively looking at it.

 

To be really paranoid, and for best practice, I should have a 3rd copy off site. At the moment I don't have any plans for that.

 

If people have a small enough data set, cloud storage may be effective.