Raid 5 Recovery Questions

[paultt]

On a 4 disk synology 2 drives have been formatted by accident which doesn't not allow the raid 5 / storage pool to be rebuilt and recovered. Can I clone one of the existing unformatted drives whereby hopefully from the 3 drives I maybe be able to rebuild the raid and recover data, or will the data be corrupted zero bytes? or is there an easier way to recover the formatted drives storage partition / without causing more damage.

[Alt]

Was it a 3-disk RAID5 with a spare drive? Or it was a pure 4-disk RAID5?

[paultt]

pure 4-disk RAID5, with 2 disks accidental formatted. The two other drives you can see the raid partitions, so they are ok.

[Alt]

Unfortunately, you need 3 healthy disks to recover data from a pure 4-disk RAID5. Cloning any of the two healthy disks will not do anything.