Just doing a backup as I write this. I cannot over emphasize the importance of backing up to NON-MAGNETIC media. If you backup to another hard drive, you have a copy, NOT a backup. I use Retrospect, and have used Dantz’s back up products since 1986, when they were a Mac only product. I use Retrospect on both platforms now. it is still the best.
Back up to dvd-r with Retrospect. it checks the quality of the backup after the writing is complete and verifies the disk-writes. It is the easiest to use and yet the most powerfull backup software you can by. Even the low cost “lite” versions are very reliable.
I use Pioneer Firewire DVD burners and Ritek DVD-R media. I store the disks in archival sleeves in a closed box in a cool, dark area. And I rotate between two backup sets for every type of back up that I make.
Remember, if it’s magnetic it’s living on borrowed time.