I have a software RAID5 array with 4 + 1 disks in which 2 of the disks have failed. I'm hoping that with some percussive maintenance, I might get one of the failed disks working again long enough to do a block level copy to get the image off.
The plan would be to make images of 4 (or all 5) of the disks with dd, and then try rebuild the array on those images.
Is there something right off the bat that I've missed that would make this impossible? If not, how would I:
- Copy an image of each device to a file
- Mount these
- Reconfigure mdadm to use these images as the devices
Obviously, there are a lot of things that might have happened that make the data corrupt, but there are reasons to think the actual data might be intact across the 4 disks:
- The second disk failure might have been due to power loss
- The data I'm interested in recovering wasn't written after the first failure