On Tue, August 11, 2009 9:56 am, Oliver Martin wrote: > Hello, > > I have two raid5 arrays spanning a number of USB drives. Yesterday, I > unintentionally unplugged one of them while connecting another device > to the same hub. The drive I unplugged used to be /dev/sdh, but when I > plugged it back in, it became /dev/sdi. For md0, this didn't matter. I > re-added it and it performed a rebuild* which completed successfully. > > md1, which used to consist of sde2 and sdh2, should now contain sde2 > and sdi2. For some reason, though, the rebuild doesn't start when I add > sdi2. It seems md doesn't recognize sdi2 as the same device that used > to be sdh2. Is that correct? How can I tell md about the name change? If you look closely at the "mdadm -D" etc output that you included you will see that md1 things that sdi2 is faulty. Maybe it is. You would need to check kernel logs to be sure. > > > Thanks, > Oliver > > [*] Bitmaps are enabled on both arrays, so I was somewhat surprised > about the full rebuild; isn't that what bitmaps are supposed to prevent? Yes, bitmaps should prevent a full rebuild. I would need to see kernel logs of when this rebuild happened and "mdadm -D" the array to have any hope of guess why it didn't. NeilBrown > > > $ mdadm /dev/md1 -a /dev/sdi2 > mdadm: re-added /dev/sdi2 > > $ cat /proc/mdstat > [...] > md1 : active raid5 sdi2[0](F) sde2[2] > 488375808 blocks super 1.1 level 5, 64k chunk, algorithm 2 [2/1] > [_U] > bitmap: 0/8 pages [0KB], 32768KB chunk > > $ mdadm -D /dev/md1 > /dev/md1: > Version : 1.01 > Creation Time : Sun Apr 12 14:19:47 2009 > Raid Level : raid5 > Array Size : 488375808 (465.75 GiB 500.10 GB) > Used Dev Size : 488375808 (465.75 GiB 500.10 GB) > Raid Devices : 2 > Total Devices : 2 > Preferred Minor : 1 > Persistence : Superblock is persistent > > Intent Bitmap : Internal > > Update Time : Tue Aug 11 01:40:15 2009 > State : active, degraded > Active Devices : 1 > Working Devices : 1 > Failed Devices : 1 > Spare Devices : 0 > > Layout : left-symmetric > Chunk Size : 64K > > Name : quassel:1 (local to host quassel) > UUID : e9226e7f:cbdad2a1:481ce05b:9444d71d > Events : 106 > > Number Major Minor RaidDevice State > 0 0 0 0 removed > 2 8 66 1 active sync /dev/sde2 > > 0 8 130 - faulty spare /dev/sdi2 > > $ mdadm -E /dev/sde2 > /dev/sde2: > Magic : a92b4efc > Version : 1.1 > Feature Map : 0x1 > Array UUID : e9226e7f:cbdad2a1:481ce05b:9444d71d > Name : quassel:1 (local to host quassel) > Creation Time : Sun Apr 12 14:19:47 2009 > Raid Level : raid5 > Raid Devices : 2 > > Avail Dev Size : 976751736 (465.75 GiB 500.10 GB) > Array Size : 976751616 (465.75 GiB 500.10 GB) > Used Dev Size : 976751616 (465.75 GiB 500.10 GB) > Data Offset : 264 sectors > Super Offset : 0 sectors > State : clean > Device UUID : 0fcc7d6d:0ec92b47:c371f8e6:bd7d2cac > > Internal Bitmap : 2 sectors from superblock > Update Time : Tue Aug 11 01:40:18 2009 > Checksum : 4290b585 - correct > Events : 108 > > Layout : left-symmetric > Chunk Size : 64K > > Array Slot : 2 (failed, failed, 1) > Array State : _U 2 failed > > $ mdadm -E /dev/sdi2 > /dev/sdi2: > Magic : a92b4efc > Version : 1.1 > Feature Map : 0x1 > Array UUID : e9226e7f:cbdad2a1:481ce05b:9444d71d > Name : quassel:1 (local to host quassel) > Creation Time : Sun Apr 12 14:19:47 2009 > Raid Level : raid5 > Raid Devices : 2 > > Avail Dev Size : 976751736 (465.75 GiB 500.10 GB) > Array Size : 976751616 (465.75 GiB 500.10 GB) > Used Dev Size : 976751616 (465.75 GiB 500.10 GB) > Data Offset : 264 sectors > Super Offset : 0 sectors > State : clean > Device UUID : 5ba69d85:c46d6bb0:bf71606e:2877b067 > > Internal Bitmap : 2 sectors from superblock > Update Time : Mon Aug 10 15:32:23 2009 > Checksum : 6db9f21 - correct > Events : 28 > > Layout : left-symmetric > Chunk Size : 64K > > Array Slot : 0 (failed, failed, 1) > Array State : _u 2 failed > -- > 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
