Hi Neil, looking at it again I think the following happened: When the disk was removed, the entry got the status "missing", which is correct. When I re-added the same disk (actually I used add, re-add doesn't work with containers) the "missing" status isn't cleared, as can be seen. But it is recognised as belonging to its original slot, albeit the missing status isn't cleared, the other status (failed, offline) can stay as they are. When I now add another disk (a spare) the slot of the missing disk is re-used, as it is marked "missing". Only by removing that disk, zeroing the superblock and adding it again, i.e. effectively adding a new disk, the total amount of slots is increased to 6. just my two cents, Albert On 1 August 2012 10:29, Albert Pauw <albert.pauw@xxxxxxxxx> wrote: > Hi Neil, > > here is a procedure which shows you another problem. It has to do with the > table produced at the end of the mdadm -E command, showing the disks and > their status. Seems when a disk has failed and another added, the failed one > disappears. > > Hope you can find the problem and fix it. > > Regards, > > Albert > > Here is the exact procedure which shows the problem: > > Create a container with 5 disks: > > mdadm -CR /dev/md127 -e ddf -l container -n 5 /dev/loop[1-5] > > Physical Disks : 5 > Number RefNo Size Device Type/State > 0 d1c8c16e 479232K /dev/loop1 Global-Spare/Online > 1 6de79cb6 479232K /dev/loop2 Global-Spare/Online > 2 b5fd1d6c 479232K /dev/loop3 Global-Spare/Online > 3 0be2d310 479232K /dev/loop4 Global-Spare/Online > 4 5d8ac3d0 479232K /dev/loop5 Global-Spare/Online > > > Create a RAID 5 set of 3 disks in container: > > mdadm -CR /dev/md0 -l 5 -n 3 /dev/md127 > > Physical Disks : 5 > Number RefNo Size Device Type/State > 0 d1c8c16e 479232K /dev/loop1 active/Online > 1 6de79cb6 479232K /dev/loop2 active/Online > 2 b5fd1d6c 479232K /dev/loop3 active/Online > 3 0be2d310 479232K /dev/loop4 Global-Spare/Online > 4 5d8ac3d0 479232K /dev/loop5 Global-Spare/Online > > > Create a RAID 1 set of 2 disks in container: > > mdadm -CR /dev/md1 -l 1 -n 2 /dev/md127 > > Physical Disks : 5 > Number RefNo Size Device Type/State > 0 d1c8c16e 479232K /dev/loop1 active/Online > 1 6de79cb6 479232K /dev/loop2 active/Online > 2 b5fd1d6c 479232K /dev/loop3 active/Online > 3 0be2d310 479232K /dev/loop4 active/Online > 4 5d8ac3d0 479232K /dev/loop5 active/Online > > > Fail first disk in RAID 5 set: > > mdadm -f /dev/md0 /dev/loop1 > > Physical Disks : 5 > Number RefNo Size Device Type/State > 0 d1c8c16e 479232K /dev/loop1 active/Offline, Failed > 1 6de79cb6 479232K /dev/loop2 active/Online > 2 b5fd1d6c 479232K /dev/loop3 active/Online > 3 0be2d310 479232K /dev/loop4 active/Online > 4 5d8ac3d0 479232K /dev/loop5 active/Online > > > Remove failed disk: > > mdadm -r /dev/md0 /dev/loop1 > > Physical Disks : 5 > Number RefNo Size Device Type/State > 0 d1c8c16e 479232K active/Offline, Failed, Missing > 1 6de79cb6 479232K /dev/loop2 active/Online > 2 b5fd1d6c 479232K /dev/loop3 active/Online > 3 0be2d310 479232K /dev/loop4 active/Online > 4 5d8ac3d0 479232K /dev/loop5 active/Online > > > Add failed disk back: > > mdadm -a --force /dev/md0 /dev/loop1 > > Physical Disks : 5 > Number RefNo Size Device Type/State > 0 d1c8c16e 479232K /dev/loop1 active/Offline, Failed, Missing > 1 6de79cb6 479232K /dev/loop2 active/Online > 2 b5fd1d6c 479232K /dev/loop3 active/Online > 3 0be2d310 479232K /dev/loop4 active/Online > 4 5d8ac3d0 479232K /dev/loop5 active/Online > > > Add spare disk to container: > > mdadm -a --force /dev/md0 /dev/loop6 > > Physical Disks : 5 > Number RefNo Size Device Type/State > 0 6de79cb6 479232K /dev/loop2 active/Online > 1 b5fd1d6c 479232K /dev/loop3 active/Online > 2 0be2d310 479232K /dev/loop4 active/Online > 3 5d8ac3d0 479232K /dev/loop5 active/Online > 4 1dcfe3cf 479232K /dev/loop6 active/Online, Rebuilding > > This is wrong! Physical disks should be 6 now! > > Removed failed disk (which is missing from list now!) again, zero superblock > and add again: > > mdadm -r /dev/md0 /dev/loop1 > mdadm --zero-superblock /dev/loop1 > mdadm -a --force /dev/md0 /dev/loop1 > > > Physical Disks : 6 > Number RefNo Size Device Type/State > 0 6de79cb6 479232K /dev/loop2 active/Online > 1 b5fd1d6c 479232K /dev/loop3 active/Online > 2 0be2d310 479232K /dev/loop4 active/Online > 3 5d8ac3d0 479232K /dev/loop5 active/Online > 4 1dcfe3cf 479232K /dev/loop6 active/Online > 5 8147a3ef 479232K /dev/loop1 Global-Spare/Online > > And there they are, all 6 of them. > > -- 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
