Sorry again, just noticed that the removing of the slot of the missing drive is triggered by a rebuild. In fact, even a failed (but not missing) drive is removed as well. I noticed this by the following: - started with 6 disks - created md0 with 5 disks - failed one disk in md0 - the mdadm -E table is shown very shortly with 6 disks, one failed, but when the rebuild kicks in, the failed disk entry is removed, 5 entries remain. Albert On 1 August 2012 18:46, Albert Pauw <albert.pauw@xxxxxxxxx> wrote: > 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
