I have 11 drives in a RAID 6 array. 6 are plugged into one esata enclosure, the other 4 are in another. These esata cables are prone to loosening when I'm working on nearby hardware. If that happens and I start the host up, big chunks of the array are missing and things could get ugly. Thus I cooked up a custom startup script that verifies each device is present before starting the array with mdadm --assemble --no-degraded -u 4fd7659f:12044eff:ba25240d: de22249d /dev/md3 So I thought I was covered. In case something got unplugged I would see the array failing to start at boot and I could shut down, fix the cables and try again. However, I hit a new scenario today where one of the plugs was loosened while everything was turned on. The good news is that there should have been no activity on the array when this happened, particularly write activity. It's a big media partition and sees much less writing then reading. I'm also the only one that uses it and I know I wasn't transferring anything. The system also seems to have immediately marked the filesystem read-only, because I discovered the issue when I went to write to it later and got a "read-only filesystem" error. So I believe the state of the drives should be the same - nothing should be out of sync. However, I shut the system down, fixed the cables and brought it back up. All the devices are detected by my script and it tries to start the array with the command I posted above, but I've ended up with this: md0 : inactive sdn1[1](S) sdj1[9](S) sdm1[10](S) sdl1[11](S) sdk1[12](S) md3p1[8](S) sdc1[6](S) sdd1[5](S) md1p1[4](S) sdf1[3](S) sdh1[0](S) 16113893731 blocks super 1.2 Instead of all coming back up, or still showing the unplugged drives missing, everything is a spare? I'm suitably disturbed. It seems to me that if the data on the drives still reflects the last-good data from the array (and since no writing was going on it should) then this is just a matter of some metadata getting messed up and it should be fixable. Can someone please walk me through the commands to do that? Mike -- 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
