What is RAID recovery?

Often people who deal with RAID arrays or NAS (Network Attached Storage) devices working under the RAID technology, don not quite understand the difference between RAID recovery and data recovery. Users believe that if they reconstructed the RAID array using special software, they immediately get access to the data on the array or can copy the recovered data to another storage. In fact, RAID recovery software performs another task, namely – RAID array configuration recovery. Array configuration includes:

  • Disk order
  • What disk was the first in the array
  • Block size
  • Start offset
  • Parity blocks rotation (for RAID 5/RAID 6/RAID 50/RAID 60)

No doubt, this is very valuable information, but knowing only the array configuration a user can't get access to the files. Only a very Linux savvy user can transfer the RAID configuration information to a controller and get access to the original array. In all other cases, a user will have to use an additional tool to recover files.

When setting an array up, a user chooses the array type - RAID 0, RAID 1, RAID 10, RAID 5 or RAID 6, while all other parameters are usually configured without a user's participation. That's why there is no way to just peek into the RAID array user manual and find out a configuration.

So, if you faced with a situation when something has failed in the RAID array resulting in no access to the data anymore, first you need to decide which way to choose – restore the RAID configuration and then recover the data, or you don't need the array recovery stage and you can immediately use data recovery software.

When do I need to recover RAID?

  • If your RAID was built with a RAID-controller, you definitely need to get through the RAID recovery stage.
  • If you have a NAS, first try to run a file recovery software, for example ReclaiMe File Recovery. The fact is that NAS uses Linux drivers to create an array - md-raid or LVM. If the metadata records are not damaged, the software can easily read them. If you tried to run ReclaiMe File Recovery, but the software doesn't show an array volume, or the recovered files are damaged, you need to get through the RAID parameters recovery step, and only after that you can get back to data recovery.

How to recover RAID array parameters?

  1. Unplug the disks from a RAID controller or a NAS device.
  2. Connect the disks to a Windows PC. It's recommended connect them directly to a PC motherboard. But if your motherboard has not enough SATA ports, you can use USB-to-SATA adapters with power supply.
    3. How to connect the NAS disks to a PC via USB
  3. Download and run array parameters recovery software – ReclaiMe Free RAID Recovery.
  4. Choose all the array or NAS disks and specify the array type you need to restore. If you have two disks, then mostl likely it is RAID 0; if you have three disks, it is RAID 5; In case of four disks you have quite a lot of possible array types – RAID5, RAID 10 or RAID 6. If you don't know exactly your array type, you need to go through all three options.
    5. ReclaiMe Free RAID - disk selection
  5. As soon as the software detects all the parameters you'll be prompted to Run ReclaiMe to recover data. When you click the button you can download ReclaiMe or run it if the software has been already installed on the PC. It will immediately start in the RAID recovery mode.
  6. Let the software scan the filesystem, and then check the quality of the recovery in Preview.
  7. If the quality is good you need to purchase a license key to save the data. Notice that you also need an additional storage equal to the size of the recovered data.

Still have questions?