Hello. I have an issue concerning a broken RAID of unsure pedigree. Examining the drives tells me the block sizes are not the same, as listed in the email. > I certainly won't be easy. Though if someone did find themselves in that > situation it might motivate me to enhance mdadm in some way to make it easily > fixable. I seem to be your motivation for making this situation fixable. Somehow I managed to get drives with an invalid block size. All worked fine until a drive dropped out of the RAID5. When attempting to replace, I can re-create the RAID, but it cannot be of the same size because the 1024-sector drives are "too small" when changed to 2048-sector, exactly as described. Are there any recovery options I could try, including simply editing the header? mdadm --examine of all drives in the RAID: /dev/sdb3: Magic : a92b4efc Version : 1.2 Feature Map : 0x0 Array UUID : 9759ad94:75e30b6b:8a726b4d:177a6eda Name : leyline:1 (local to host leyline) Creation Time : Mon Sep 12 13:19:00 2011 Raid Level : raid5 Raid Devices : 5 Avail Dev Size : 3906525098 (1862.78 GiB 2000.14 GB) Array Size : 15626096640 (7451.10 GiB 8000.56 GB) Used Dev Size : 3906524160 (1862.78 GiB 2000.14 GB) Data Offset : 2048 sectors Super Offset : 8 sectors State : clean Device UUID : 872097fa:3ae66ab4:ed21256a:10a030c9 Update Time : Fri Jun 1 03:11:54 2012 Checksum : 6d627f7a - correct Events : 2127454 Layout : left-symmetric Chunk Size : 512K Device Role : Active device 1 Array State : AAAA. ('A' == active, '.' == missing) Magic : a92b4efc Version : 1.2 Feature Map : 0x0 Array UUID : 9759ad94:75e30b6b:8a726b4d:177a6eda Name : leyline:1 (local to host leyline) Creation Time : Mon Sep 12 13:19:00 2011 Raid Level : raid5 Raid Devices : 5 Avail Dev Size : 3906525098 (1862.78 GiB 2000.14 GB) Array Size : 15626096640 (7451.10 GiB 8000.56 GB) Used Dev Size : 3906524160 (1862.78 GiB 2000.14 GB) Data Offset : 2048 sectors Super Offset : 8 sectors State : clean Device UUID : 2ea285a1:a2342c24:ffec56a2:ba6fcf07 Update Time : Fri Jun 1 03:11:54 2012 Checksum : fae2ea42 - correct Events : 2127454 Layout : left-symmetric Chunk Size : 512K Device Role : Active device 0 Array State : AAAA. ('A' == active, '.' == missing) /dev/sdc3: Magic : a92b4efc Version : 1.2 Feature Map : 0x0 Array UUID : 9759ad94:75e30b6b:8a726b4d:177a6eda Name : leyline:1 (local to host leyline) Creation Time : Mon Sep 12 13:19:00 2011 Raid Level : raid5 Raid Devices : 5 Avail Dev Size : 3906525098 (1862.78 GiB 2000.14 GB) Array Size : 15626096640 (7451.10 GiB 8000.56 GB) Used Dev Size : 3906524160 (1862.78 GiB 2000.14 GB) Data Offset : 2048 sectors Super Offset : 8 sectors State : clean Device UUID : 2ea285a1:a2342c24:ffec56a2:ba6fcf07 Update Time : Fri Jun 1 03:11:54 2012 Checksum : fae2ea42 - correct Events : 2127454 Layout : left-symmetric Chunk Size : 512K Device Role : Active device 0 Array State : AAAA. ('A' == active, '.' == missing) /dev/sdd3: Magic : a92b4efc Version : 1.2 Feature Map : 0x0 Array UUID : 9759ad94:75e30b6b:8a726b4d:177a6eda Name : leyline:1 (local to host leyline) Creation Time : Mon Sep 12 13:19:00 2011 Raid Level : raid5 Raid Devices : 5 Avail Dev Size : 3906524160 (1862.78 GiB 2000.14 GB) Array Size : 15626096640 (7451.10 GiB 8000.56 GB) Data Offset : 1024 sectors Super Offset : 8 sectors State : clean Device UUID : 8d656a1d:bbb1da37:edaf4011:1af2bbb9 Update Time : Fri Jun 1 03:11:54 2012 Checksum : ab4c6863 - correct Events : 2127454 Layout : left-symmetric Chunk Size : 512K Device Role : Active device 3 Array State : AAAA. ('A' == active, '.' == missing) /dev/sde3: Magic : a92b4efc Version : 1.2 Feature Map : 0x0 Array UUID : 9759ad94:75e30b6b:8a726b4d:177a6eda Name : leyline:1 (local to host leyline) Creation Time : Mon Sep 12 13:19:00 2011 Raid Level : raid5 Raid Devices : 5 Avail Dev Size : 3906524160 (1862.78 GiB 2000.14 GB) Array Size : 15626096640 (7451.10 GiB 8000.56 GB) Data Offset : 1024 sectors Super Offset : 8 sectors State : clean Device UUID : 37bb83bd:313c9381:cabff9d0:60bd205c Update Time : Wed May 23 03:30:50 2012 Checksum : f72e6959 - correct Events : 2004256 Layout : left-symmetric Chunk Size : 512K Device Role : spare Array State : AAAA. ('A' == active, '.' == missing) /dev/sdf: Magic : a92b4efc Version : 1.2 Feature Map : 0x0 Array UUID : 9759ad94:75e30b6b:8a726b4d:177a6eda Name : leyline:1 (local to host leyline) Creation Time : Mon Sep 12 13:19:00 2011 Raid Level : raid5 Raid Devices : 5 Avail Dev Size : 3907027120 (1863.02 GiB 2000.40 GB) Array Size : 15626096640 (7451.10 GiB 8000.56 GB) Used Dev Size : 3906524160 (1862.78 GiB 2000.14 GB) Data Offset : 2048 sectors Super Offset : 8 sectors State : clean Device UUID : e16d4103:cd11cc3b:bb6ee12e:5ad0a6e9 Update Time : Fri Jun 1 03:11:54 2012 Checksum : e287a82a - correct Events : 0 Layout : left-symmetric Chunk Size : 512K Device Role : spare Array State : AAAA. ('A' == active, '.' == missing) -- James Moore -- James Moore -- 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