I recently had the experience of having to run down the cause of a few clients not being able to access their email systems. I quickly learned that the servers which hosted those email systems had been taken down by the hosting company. Further checking revealed that the issue was a failure of a large multiply redundant array. This was not the failure of a single drive nor even that of a single array; but, rather, it was a simultaneous failure of two synchronized arrays. The likelihood of such a failure would seem to be astronomically rare; but, it was the second such failure in this particular data center in just over 2 years. Because of the size and complexity of the arrays, it took over 8 hours to get a full backup and then another 16 hours to build a replacement array and restore the data before the servers could start to be brought back online (and the hosted email systems to become accessible once again).
This event highlights an important point about trusting the cloud to securely protect your personal or business data. The cloud does represent a far more reliable storage technique than your hard drive in your computer but it is not perfect; failures can and do happen. As a result, I continue to recommend that all users of electronic devices personally backup their data and store the media in a cool, dry, safe location. Backup often (any time you have worked an amount that you do not want to have to repeat) using appropriate media (CD’s, DVD’s, USB sticks, button drives, etc.).