On Tue, 29 Jun 2010 06:26:17 +0000 (UTC) Dave W <dave+gmane@xxxxxxxxxxxx> wrote: > Previously, I wrote: > > > After making some changes in the bios to my boot order, my 5-drive RAID6 > > stopped assembling. Three of the five known-good drives suddenly stopped > > getting added to the right slots. There are no disk errors in the logs and > > I can read from the drives with no problems. > > Any help with this one? My disks are fine but mdadm seems confused about which > slots they're supposed to be in. How can I tell mdadm to put them in the right > slots? This is very odd.... that should not happen. I think I've seen a few reports of something like that happening and I'm beginning to wonder if I broke something subtle.... What kernel/mdadm version are you using. You should use "mdadm --examine" to see the configuration of the array, and make sure that configuration is copied exactly when you creat a new array - same chunk size, same layout, same metadata version etc. You need to list the 5 drives in the correct order, from slot 0 to slot 4. Clearly d1 is2 and e1 is 3. Presumably b1 is 0, c1 is 1, f1 is 4. So a command like: mdadm --create /dev/md0 --assume-clean --metadata=XX --chunk=XX --level=6 --raid-devices=5 /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1 /dev/sdf1 is likely to work (if you get all the 'xx' right). Keep a copy of the "mdadm --examine" output and compare it with the output after runing the --create and make sure everything is still the same (e.g. Data Offset could be changed - that would be awkward). Then try "fsck -n -f /dev/md0" to see if fsck thinks it is OK. If it is, try mounting "-o ro" and check that the data looks OK. If it passed all that you should be fine - you might like to echo repair > /sys/block/md0/md/sync_action to make sure all the parity blocks are correct. If 'fsck' fails, you might like to try again, re-arranging the devices that you aren't sure of. Good luck. NeilBrown > > Thanks, > Dave > > # mdadm --stop /dev/md0 > mdadm: stopped /dev/md0 > # mdadm -v -Af /dev/md0 /dev/sd[bcdef]1 > mdadm: looking for devices for /dev/md0 > mdadm: /dev/sdb1 is identified as a member of /dev/md0, slot 7. > mdadm: /dev/sdc1 is identified as a member of /dev/md0, slot 6. > mdadm: /dev/sdd1 is identified as a member of /dev/md0, slot 2. > mdadm: /dev/sde1 is identified as a member of /dev/md0, slot 3. > mdadm: /dev/sdf1 is identified as a member of /dev/md0, slot 5. > mdadm: no uptodate device for slot 0 of /dev/md0 > mdadm: no uptodate device for slot 1 of /dev/md0 > mdadm: added /dev/sde1 to /dev/md0 as 3 > mdadm: no uptodate device for slot 4 of /dev/md0 > mdadm: added /dev/sdf1 to /dev/md0 as 5 > mdadm: added /dev/sdc1 to /dev/md0 as 6 > mdadm: added /dev/sdb1 to /dev/md0 as 7 > mdadm: added /dev/sdd1 to /dev/md0 as 2 > mdadm: /dev/md0 assembled from 2 drives and 3 spares - not enough to start the > array. > # > > > -- > 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 -- 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
