If I were concerned about long term storage, I would be looking at a parity RAID with a great backup routine and tested restores. Or, if your long term storage

If I were concerned about long term storage, I would be looking at a parity RAID with a great backup routine and tested restores. Or, if your long term storage can go cold, perhaps magnetic media is perfectly fine provided it isn't online much of the time, not that magnetic media can't last for many years. You'd save money with a spinning disk RAID6 array and get gobs more storage. It's all trade-offs you need to decide for yourself and your goals. If you want to be safe, replace the drives every 5 - 7 years. You will find drives that fail in 6 months and drives that last 30+ years, even from the same model line.