The long story and what I've done. /dev/md0 is assembled with 4 drives /dev/sda3 /dev/sdb3 /dev/sdc3 /dev/sdd3 2 weeks ago, mdadm marked /dev/sda3 as failed. cat /proc/mdstat showed _UUU. smarctl also confirmed that the drive was dying. So I shutdown the server and until I received a replacement drive. This week, I replaced the dying drive with my new drive. Booted into single user mode and did this: mdadm --manage /dev/md0 --add /dev/sda3 a cat of /proc/mdstat confirmed the resyncing process. The last time I checked it was up to 11%. After a few minutes later, I noticed that the syncing stopped. A read error message on /dev/sdd3 (have a pic of it if interested) appear on the console. It appears that /dev/sdd3 might be going bad. A cat /proc/mdstat showed _U_U. Now I panic, and decide to leave everything as is and to go to bed. The next day, I shutdown the server and reboot with a live usb distro (Ubuntu rescue remix). After booting into the live distro, a cat /proc/mdstat showed that my /dev/md0 was detected but all drives had an (S) next to it. i.e. /dev/sda3 (S)... Naturally I don't like the looks of this. I ran ddrescue to copy /dev/sdd onto my new replacement disk (/dev/sda). Everything, worked, ddrescue got only one read error, but was eventually able to read the bad sector on a retry. I followed up by also cloning with ddrescue, sdb and sdc. So now I have cloned copies of sdb, sdc and sdd to work with. Currently running mdadm --assemble --scan, will activate my array, but all drives are added as spares. Running mdadm --examine on each drives, shows the same Array UUID number, but the Raid Devices is 0 and raid level is -unknown- for some reason. The rest seems fine and makes sense. I believe I could re-assemble my array if I could define the raid level and raid devices. I wanted to know if there are a way to restore my superblocks from the examine command I ran at the beginning? If not, what mdadm create command should I run? Also please let me know if drive ordering is important, and how I can determine this with the examine output I'll got? Thank you. -- 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
