DBCC CheckDB : Operating System Error 27(The drive cannot find the sector requested)
Turns out the problem had to do with the SAN returning invalid sectors during disk IO events. What had happened was that the disk had had 400Gb of unusable space removed, and something went sideways in the disk definition in the SAN. The solution was to shrink the disk by 10Gb then grow back that 10Gb to reestablish the disk definition in the SAN. Once that was complete, suddenly everything was fine. Not at all what I expected but I wanted to show what the solution was, because I think it's important that &quot;rock solid, never has an error, why are you even looking at that&quot; systems need to be included in a full error analysis.