Long-term storage on ANY high-density device is risky. That is why I always
tell people to make two copies of everything. This is not expensive if
external Hard Disk Drives are used and put on shelves.
The cost of large servers is not within the budgets of most archives. Also,
most people are using RAID-5 and RAID-5 is a very bad idea since it is
possible that you can lose ALL of the data in the server!
RAID-6 duplicates everything so it is much, much safer, but also more