A couple years ago, I learned my lesson. I had bought a WD My Book Thunderbolt external RAID. I didn't have a backup plan of course; it failed within a year, and I lost everything—this was about a year ago.
I went out and bought two 8TB Seagate Expansion Desktop Drives, one as my main storage, and one for backup. I signed up with Crashplan, a service that would backup my files to it's cloud as well as do the job of backing up to my local external backup drive.
A couple of months ago the backup drive died. Within the same week one of my wife's external drives died.
I invested in a Synology NAS and set up a RAID 6 to throw all my files onto, with plans to attach a 2nd external drive to back up the NAS—but of course, before I get a chance to back up my main Seagate drive to the NAS, my Mac is telling me it has a problem (unfortunately I didn't write down what it said), that it has been set to read-only, and I need to back it up before it fails completely.
It feels like this is happening a bit too often to blame on "Well sometimes ya just get a bad one!", and I'm wondering if I am overlooking other factors?
Could it be an electrical issue? My house is about 120 years old, but we had the knob & tube wiring replaced when we moved in and a new breaker box installed. All my computer hardware is plugged into a couple surge protectors which are in turn plugged into a UPS batter backup/surge protector.
Could there be a problem with my computer, doing something to the hard drives to mess them up?
Am I just overusing or overfilling the drives? My work is in graphic design, photography, and video editing, so I'm typically working with some big files, lots of caches, etc. Also I know when Crashplan was backing up to that one external it was telling me it was nearly full. Perhaps I need to be running First Aid on the drives, or rebuilding the directories with Diskwarrior on a regular basis?