I'm more than a little reluctant to share this tale because it doesn't present my native intelligence in a very good light, but perhaps sharing this cautionary story will prevent other near or real disasters.
For about five years I have kept all of my pathology-related work on a single external 250 GB USB hard drive..... You can guess what's coming. A few weeks ago I noticed that it was taking longer than normal to access files on the drive... Sign #1 which I ignored. About a week after that I noticed that the drive was occasionally making a "clunking" sound when it powered down... .Sign #2 which I also ignored. Then, you guessed it, one Monday morning I powered it up and it wouldn't function at all. This drive contained every PowerPoint talk I've ever given, every digital photo I've ever taken, all the textbooks I've written and edited, including all the photos, and, importantly, everything relating to the upcoming 4th series AFIP fascicle on the Upper Aerodigestive Tract which is nearing completion. I had backups for some but probably less than 30% of this material and, in particular, I had no backup for the new ENT fascicle and several new talks that I had developed over the Spring. I worked in the construction industry to help put myself through college, and I acquired a robust vocabulary of curse words which I unleased explosively at the time, almost entirely directed at my stupidity rather than the hard drive's failure. I then began to feel really sick to my stomach.
It took several days to find out if I was to be saved, but fortunately, in this instance luck won out over stupid, and I was able to have all of my data retrieved thanks to a wonderful company in town that specializes in hard drive recovery at a VERY modest price. I would gladly have paid, much, MUCH more!
The moral of this story is simple. A hard drive is a mechanical device. It's not a question of IF it will fail, it's simply a matter of WHEN it will fail. If you don't have up-to-date backups, you'll be in trouble when this inevitably happens to you and luck may not win this time. Often the drive will give you warning signs before it fails completely. DON'T IGNORE THEM!
I replaced the defective hard drive with a RAID hard drive system running two 1 TB hard drives in parallel. In theory if one fails the data is safe on the other and the failed drive can be replaced. That's a first step to data safety, but it's really not sufficient. Off-site backup is really mandatory if you care about your data. If you're compulsive you can do this by methodically copying new files onto a USB "thumb drive," carrying them home and downloading them to a backup hard drive outside of your office. Sooner or later, though, you'll forget to do this, or worse, you'll get confused and replace the new data with an old file. A much better solution is an on-line, off-site automated backup system. These are relatively inexpensive and virtually guarantee data survival.
If a hard drive failure happens to you I hope you're better prepared than I was and, if you aren't, good luck! By all means, however, if you don't have backups search for a data recovery company. They have very sophisticated tools and may well be able to retrieve everything from your damaged hard drive, or at least much of the material. These are the same tools used to extract data from flight recorders after airplane crashes. If necessary, these folks will go as far as disassembling your hard drive in a clean room and installing the media in a new drive system. But expect to pay.
...and then there are viruses to worry about!