What's a good backup practice nowadays? Supposed you have 500 gigs of archive data. It's not saved anywhere else. Would you copy it to an external HD with a USB 2.0, USB 3.0, or SATA interface? Or DVDs? Blu-Ray?
I know someone who was asked this question at work. He suspects the 1 terabyte internal HD that is networked accessed by people who work on contract proposals is going to fail. The server equipment that HD sits on is old and he also suspects that this will give up the ghost too. They don't take tape backups of this drive.
I suggested they get a new HD and copy all the data. Then make physical backups.