While reloading data for WCQS in T316236 , we had to reboot wcqs1003.eqiad.wmnet several times before it would actually load the OS, and the BIOS displayed disk errors every time:
Initializing Serial ATA devices... Port A: Device initialization error Port B: MTFDDAK1T9TDT Port C: MTFDDAK1T9TDT Port D: MTFDDAK1T9TDT
Opening ticket to continue this investigation.