On Sat, Nov 23, 2013 at 8:03 PM, Stan Hoeppner <stan@xxxxxxxxxxxxxxxxx> wrote: > Parity array rebuilds are read-modify-write operations. The main > difference from normal operation RMWs is that the write is always to the > same disk. As long as the stripe reads and chunk reconstruction outrun > the write throughput then the rebuild speed should be as fast as a > mirror rebuild. But this doesn't appear to be what people are > experiencing. Parity rebuilds would seem to take much longer. "This" doesn't appear to be what SOME people, who have reported issues, are experiencing. Their issues must be examined on a case by case basis. But I, and a number of other people I have talked to or corresponded with, have had mdadm RAID 5 or RAID 6 rebuilds of one drive run at approximately the optimal sequential write speed of the replacement drive. It is not unusual on a reasonably configured system. I don't know how fast the rebuilds go on the experimental RAID 5 or RAID 6 for btrfs. -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
