“Here’s a guy who discusses SATA
vs. SCSI disk reliability. Short conclusion: actual disk failures (MTBF) are almost exactly as likely wtih cheap SATA disks as expensive SCSI disks. But the bit error rate of SATA is much higher. In other words, the likelihood of not being able to read a sector because it got corrupted on SATA is vastly higher than SCSI. By his calculation, on a 1TB disk, you have about a 56% chance of not being able to read every single sector, which means rebuilding your RAID correctly in the case of a failed disk is usually impossible…. “

http://alumnit.ca/~apenwarr/log/?m=200809