Failure does not necessacarily = outage

Note that these systems use RAID disk so a disk failure, which happens regularly, does not equal an outage, nor does cable, SFP, controller etc. failure because these systems are redundant. I see user error, like incorrect configurations, not updating code or updating it incorrectly etc. as the #1 cause of true outages where users cannot access data, so I am not exactly sure what this study is saying because hardware failure is rarely the cause of an outage.

I will agree that many disk failures are not really disk failures at all, but simply disks that are erroneously indicated as failed by the system because of errant code or another device like a cable or SFP inserting errors inteh system. Many "defective" drives that are called in for replacement are actually fine.

Mine is the one with the hot spare drive in the pocket.