Is it possible to recover a RAID 5? After losing the "/proc/mdstat" and run by mistake "mdadm --create --verbose /dev/md0 --level=5 --raid-devices=4 /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1" instead of mdadm --assemble --scan.
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4Do nothing else. Send the four disks to a professional data recovery company.– Michael HamptonJul 13, 2015 at 18:04
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4Or restore from backup.– SvenJul 13, 2015 at 18:06
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Restoring from backup is probably quicker...– userJul 13, 2015 at 18:09
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5Either way, I agree with the sentiment expressed in Michael Hampton's comment: do nothing. At least not until you have a solid plan for how to proceed. Actions not thought through in instances like this are what really loses you data. If you have the disk space to spare, I would also suggest making bit-level copies of the relevant disks now.– userJul 13, 2015 at 18:09
1 Answer
It helps if you know the configuration of the original RAID5. Perhaps you have saved the output of a prior run of mdadm --examine.
There are some RAID recovery tools you can try like R-Studio / UFSexplorer / ReclaiMe
I often work on failed mdadm RAID systems and can say recovery is almost always possible. But do not perform any action that writes to the RAID member drives unless you are very sure of what you are doing. Or you will just be digging a deeper hole. As suggested by Michael Kjörling making drive images is a good first step.