To all who have contributed to mdadm I thank you. Last week for the third time in my life I was able to recover from certain disaster. This time it was a 4 disk complex raid10 that had lost 1 disk and thrown another. Smartctl said that one disk was genuinely faulty and in replacing the drive I hadn't appropriately re-secured the sata cable to the drive above it. Long story short is the array started, but disk 4 was flakey. Metadata was updated on 2 drives and upon reboot (after seeing critical messages echoed to my screen about XFS saying "nope") the array couldn't be automatically started. mdadm --misc -E /dev/sdb and I could forcibly re-create the array, after following the iteratively scary recovery guide on your wiki. I wasn't writing to the array when it became corrupted so felt confident in my decision - well, my choices were to either definitely lose approx 4-5 TB of data or go for a seat of my pants hail mary... I got to thank Neil in person at LCA 2013 in Canberra, but I had to extend my thanks to the wider community after this third miracle. I can't imagine such a recovery with a hardware based solution. i probably wouldn't have had this issue with a proper drive array, but this is a re-purposed pc->server conversion.. Thanks :) p.s. the other 2 miracles were recovering a RAID5 that had thrown 2 disks (bad PSU) and reshaping a 2 disk RAID 1 array to a 3 disk RAID 5; amazing!! -- 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
