Its easy to predict that all hard drives will fail, so I always have a 1-3 copies sitting on a shelf.
For boot disks there is one verified 7200rpm 1TB backup. For irreplaceable CD and Dvd rips I have 2-3 5400 2TB backups stored in different locations.
To duplicate/image disks I use an old Xp pc with Acronis True Image Home and use the disk clone utility. I installed two Kingwin hot swap sata enclosures. Its quite automated and a 1TB boot drive takes a whole 1 hr to backup. Never lost a single file because I developed a simple strategy and plan for the worst. Not buying Seagate also puts one ahead of the crowd.
My daughter recently lost 3 years of photographs, even though I had warned her ahead of time.