Recover a Failed RAID Array with Disks that Haven’t Actually Failed
I recently ran into an issue where I loaded a saved configuration from my BIOS that ended up dismembering my RAID10 array. When I loaded the saved configuration, it reset the SATA mode in my BIOS to AHCI instead of RAID. Without noticing, I saved my configuration and rebooted. When I did this, two of the disks from my RAID setup fell out of the array and I was unable to access any of my data, even after setting the mode back to RAID. In this guide I’m going to show you how I managed to recreate the array without losing any of my data.
Here is what my RAID configuration screen showed when I rebooted after changing my SATA configuration back to RAID:
Thankfully, my OS is installed to a solid state hard drive so that I was still able to boot into Windows. If your OS was installed to the RAID array, I would recommend installing Linux to a bootable USB stick.
I take absolutely no responsibility for any loss of your data. This is what worked for me and has worked for others. Follow this guide at your own risk.
- TestDisk by Christophe Grenier
If you are able to boot into Windows, grab the Windows version; otherwise you may have to grab the Linux one if you’re using a bootable USB stick.
Take note of ALL the specifics of your current RAID array, such as the type, stripe size, etc. We will need to recreate the array with the exact same settings later on, so MAKE SURE YOU TAKE NOTE OF THESE! It is also very important that your disks are in the correct order, if you disconnected any of the SATA cables inside your machine and tried swapping the drives around, this will not work. You must ensure that the drives are in the same order that the array was created in.
I will be assuming you’re using Intel Rapid Storage Technology. If you’re not, the steps should be similar.
The first thing you’ll need to do is reset all the disks to Non-RAID:
Next, select the RAID disks that you’d like to reset to non-RAID, in my case it was both disks:
Enter when you’re done selecting the disks. You should now see that all the disks are Non-RAID Disks:
Next, hit the
Create RAID Volume option. Create your new array with the exact same settings as your previous array:
Confirm that you want to create the array, even though it says all data will be lost:
You should now see your new RAID array created with the same settings as before:
Next you’ll have to boot into your operating system, whether it be Windows or your Live USB stick. I will only be covering the Windows way since I was still able to boot into it.
Using TestDisk to Restore your Partitions
Once you boot into your OS, fire up TestDisk. Your first step will be to choose whether or not you want to use a log file. I chose
No Log since I didn’t feel the need to log anything:
Next, select your RAID Volume and hit
Now you’ll have to select the partition type you were using previously. TestDisk may ‘hint’ what partition type you were using and automatically highlight it for you. Make sure to confirm it’s the right type, and hit the
Next, hit the
Analyse item to search for your missing partitions:
Enter on the
Quick Search item to start the search:
With any luck, it should find and list your missing partitions. It found all mine successfully, so hit
Enter to continue.
At this stage, if it didn’t find all your partitions you could choose to do a deeper search, however since it found all of mine I chose the
Write option to write the partition structure to the disk:
Once it has finished writing the partition structure to disk, you will need to reboot your machine. After the reboot, you should have all your data back. If your OS was on your RAID array, you may need to use a bootable Windows installation disk and repair your boot manager. For help on how to do use, see this Microsoft article. I would suggest using each of the options separately. Use
/FixBoot, and finally
/RebuildBcd. Hopefully this should fix your startup issues.
Hopefully this has helped you recover your data. It really shows how important it is to have a backup elsewhere, maybe on an external drive or in the cloud (both would be ideal) just in case of a massive RAID problem. It really is a scary sight when you see that failure message. Good luck! I have to thank this post from Extreme Overclocking for guiding me through this.