My pastor friend was asking me yesterday what to do about an external hard drive that seems to have failed. When he plugs it into his computer, it gives an error that it can't recognize the device.
Unfortunately I have a whole stack of failed external hard drives at home. I've always said that as long as data is sitting on spinning magnetic media, it's not really backed up.
But, with some external hard drives being over 200 times as large as a DVD disk, very very few people are going to take a time to make a backup. Big companies use robotic tape libraries, but those are units that probably cost more than your new car, or even as much as a house.
You might try to segregate the files you've created from the ones you've collected, and could probably collect again in the future. Make optical disk (CD or DVD) backups of your personally created files, which, unless you are into multimedia video creation, are probably considerably smaller than your whole file collection.
With such large hard drives becoming commonplace, the only real backup solution for the average person is to buy an extra external hard drive, and periodically copy the contents of the main drive to the backup drive, then disconnect the backup drive. Hopefully you'll never be in a position where both drives fail at the same time. Some product contain extra internal hard drives, and automatically perform the mirroring operation as a RAID array. Just be sure to be on the lookout for the failure light, and replace the failed drive before both internal drives fail.
He was asking me about the little small tiny USB drives, "thumb drives". A lot of people like to carry files around on them, and they might even think of them as a backup because they have no moving parts. I told him those are not guaranteed either. I've had them fail too. Again, make sure you never keep your data in only one place.
I should probably modify my maxim to say "As long as your data is on a rewritable device, it's not really backed up." The use of RAID mirroring of data to secondary drives only decreases the risk of failure.
Later in the day I was trying to copy some project files off an 8 GB SanDisk Cruzer thumb drive. But computer would not recognize the drive. I'd seen this before where sometimes one machine would not recognize the drive, but others would. So I tried a second laptop. I tried different ports, as I've occassionally seen the drive not work in one port, but work in another. Occassionally the computer would recognize the drive briefly, but most of the time it wouldn't.
I was very distressed by this. The thumb drive is less than a year old. I suspected a problem with the usb connection, but I didn't want to risk stressing the USB connector on my computer by putting pressure on the thumb drive to make better contact. So we stopped at a Best Buy store to try using the computers there. I found a laptop that would recognize the failing thumb drive, so I plugged in a second thumb drive I had, and copied over the most important files. I then bought an external USB HUB, and an 8GB PNY thumb drive. Cost: $100. PLus an hour or more trying to get the failed thumbdrive to work.
This morning I experimented with the hub. I found out if I insert the thumb drive into the hub, and flex the drive upward from the hub, it would make better contact. So I started coping off the rest of the files. But after half an hour, my hand got tired, and my grip shifted, and drive disappeared. So I tried again, this time proping the hub and thumb drive on some books on my bed, and putting some other books on the joint to create flex. (Funny pun, I was using an ActionScript 3.0 cookbook and some books about Adobe's Flex programming.) That worked, until one of my cats tried to perch on the books, and drive disappeared again. So then I tried on the kitchen table with some Bibles, and stacks of business cards. I started the copy, then took some smoked salmon to a different room, so the cats would chase me into the other room and leave the stack alone.
I have finally emptied the thumb drive. There are now three thumb drives hanging from my necklace, and one or two others in my laptop bag. They are starting to look like the digital equivalent of a sharks teeth necklace.
For your really important files, like the unique files you've created, it's probably best to copy them onto three different DVD or CD disks. (Avoid the DVD and CD rewritable disks, I have found that they have a higher error rate.) Then store each copy in a different location. If you are really paranoid, use different brands of DVD's, and different brands of DVD holders. Probably the jewelcase holders are best, since the DVD is supported without any of it's reflective surfaces being in contact with anything. For some of the plastic sleeve multiple disk holders, I've seen the reflective layer peel away from the disk when trying to remove it from the sleeve. The sleeves with dimples in them are probably least likely to havethis problem. It's probably good not to put a lot of pressure on those kids of softcases. A hard case, not overly stuffed, is another way to store the disks.