Well, from my probe of 500 servers I have at work I have seen RAID1 rebuild failing zero times and RAID6 failing once (but we did recover it). Granted, that wa

Well, from my probe of 500 servers I have at work I have seen RAID1 rebuild failing zero times and RAID6 failing once (but we did recover it). Granted, that was a bit of uncommon case where: * someone forgot to order spares after taking last one * we still had our consumable buying pipeline going thru helpdesk * helpdesk didn't had any importance communicated about it and because of some accounting bullshit the purchase got delayed long enough * the drives in question were all from some segate's fuckup of a model with much higher failure rates. One disk failed with some media errors, remaining 2 got kicked out of array for same reason during resilvering We ddrescue'd the 2 on the pair of fresh ones and the bad blocks didn't land in the same place on both drives so it made full recovery. But we did learn many lessons from that..