A couple of years ago I posted about an unlucky encounter with my Thecus N5200 Pro. On the 1st January at 06:15 I had a New Year’s present. A disk died on me. The Thecus duly notified me by starting to beep.
I still have my RAID-6 setup so there was no real problem. I have 2 redundant disks. So I went and bought a replacement and fitted it and the Thecus duly started rebuilding the RAID array with an estimated time to finish of about 1 day (5x1TB disks, so ~3TB array).
Disk prices have increased significantly since I originally bought my array but buying a single disk was not a problem. During the time that the array was rebuilding or shortly afterwards however a second disk failed just as it had 2 years ago when I ended up losing my array as the RAID-5 setup did not have any further disks. This time however there was no problem. RAID-6 saved me and the photos and backup information I had on my Thecus so I was happy and I ended up running out and buying another disk. This one triggered the array rebuild and completed successfully.
That lead me to think. A lot of people push the move to external disks as a backup alternative. Certainly this gives you online information and generally works well. I am using this device at home to keep my photos and other files and also to do a backup of my main machine to a separate location. However, what strikes me as being clear: replacing disks is expensive. Had I been using tapes for backups throwing away the 2 tapes and buying new ones would have been much cheaper than buying 2 new hard disks for my array. Of course a disk array does not provide you a site backup and also does not provide you a convenient way to store multiple backups over time. For that it is not yet cost effective.
So after this experience I am tempted to look and see if there are any small tape devices which I could attach to my PC and use that to give me these extra facilities. The hardware no doubt exists but from previous searches it is expensive and out of the price range of the average home user. That is a shame. With a lot of people now dismissing tape devices as old fashioned failure of drives in a small array like my 5-disk array may turn out to be pretty expensive (in money) or pretty costly (lost data). RAID-1 or RAID-5 sound great but can you afford for a second disk to fail while the array is rebuilding after the first disk has failed? If you can not then arrays of this type may not be for you and may lead you to a false sense of security.
The title of my original post was Unlucky Encounter… So have I just been unlucky (again) or is this sort of problem something which has happened to more people?