I had to open my file-server's housing today to replace a faulty fan. What I didn't see was that one of the sata-cables was not properly connected. The 1st thing I did after a reboot was a check of the RAID status and it showed immediately that one drive is missing. Till this moment the device was not used (however it was mounted, so I'm not 100% sure that system did nothing). I stopped md0 and re-plugged in the cable:
mdadm --stop /dev/md0 poweroff
After another reboot I checked the removed drive:
mdadm --examine /dev/sdd1 ... Checksum : 3276bc1d - correct Events : 315782 Layout : left-symmetric Chunk Size : 32K Number Major Minor RaidDevice State this 0 8 49 0 active sync /dev/sdd1 0 0 8 49 0 active sync /dev/sdd1 1 1 8 65 1 active sync /dev/sde1 2 2 8 33 2 active sync /dev/sdc1 3 3 8 17 3 active sync /dev/sdb1
I was a bit surprised that it was shown as active (even if earlier
mdadm said that this device was removed from array) and the checksum was OK. I recreated RAID with:
mdadm --assemble /dev/md0 --scan
mdadm --detail /dev/md0 showed that all drives were running and system was in "clean" state. I mounted the device md0 and then came hic-cup. I wanted to work on one of the last files that I had been using before all the situation and it was not there. In another place I missed actually all files from the directory where I was working. As far as I can see most of the files that are older than a few days are intact but some newer ones are missing.
Now the big question: what would be your advice? Is there a way to get this data? I thought about removing the drive that was earlier labeled by
mdadm and rebuild array with another HDD.
I started to back-up the drives today. After mounting md0 as read-only I run
rsync to another server. Now curious thing. I moved a week ago some directories to other array.
rsyns has shown following info on these removed dirs:
file has vanished: "/MD0/Data/_NMR_"