Wouldn’t you like to find the root cause of that downtime incident? Many people would. But experience has taught me that there is no such thing as a single root cause. Instead, there’s a chain of interrelated causes, each of which is necessary but none of which is sufficient to cause the overall problem. I am often reminded of an outage years ago. It was “caused” by a failed disk. But the disk was in a RAID5 array, and another disk in that array had failed some time previously.