you have too much time on your hands. Your server will not fail.
Since I have been doing these shared storage systems since April 2008, I have seen one server boot drive fail. However, the large media RAID Arrays fail constantly. Drive failures in these RAIDs are constantly failing. Most people cannot afford a redundant large drive array. And for those that can afford it, I have found that these very large drive arrays can become corrupt, so doing an automatic backup is just as risky. I advise people to do a manual test (like with Apple Disk Utility Repair Disk) to make sure that there is no corruption on the array. And then use one of countless programs like Super Duper, Carbon Copy Cloner, Chronosync, Retrospect, etc. to create the clone.
But since most people cannot afford a redundant drive array, I recommend alternatives, which can be anything from LTO (I like Cache-A) to small SATA or FW drives to backup individual projects.
But as for the server itself failing - not likely.