Firmware RAID drive assignment suddenly missing - How to add it back?

Question

I have an ASUS Sabretooth 990fx R2.0 motherboard, and I have three HDD's in total. 2 x 250GB Samsung EVO SSD drives and a single WD 1TB HDD.

I had set up my 2 SSD drives in RAID-1 configuration using the on-board hardware RAID, with the separate 1TB drive non-raided and used purely as a data drive.

This configuration was all working well for around the last 3 months or more until I recently started to notice an error on POST saying that the RAID array was in a "critical" state. I booted into the RAID setup and saw that the "LD" definition that I'd previously set up to contain the two SSD drives now only contains 1 drive. The other drive (according to the RAID setup utility) was "failed or disconnected", however other screens within the RAID util show the "disconnected" drive to by perfectly healthy - this is also confirmed by Windows 8.1 itself when I boot all the way into Windows and check the health of the drive from the Disk Management utility.

I do not seem to be able to edit the existing "LD" RAID definition in order to "re-assign" the drive that has seemingly unassigned itself from the array and it would appear that my only option is to delete the LD definition and re-create it, however, I'm assured that this will completely erase the entire disk when I do this, which (given that this is my Windows partition) is something I want to completely avoid.

How can I re-assign the unassigned disk to the existing RAID definition without erasing/losing any data on the currently assigned RAID disk?

Here's a single picture of the LD definition screen within the RAID utility showing the problem:

I've uploaded a gallery of screenshots of the RAID util showing other screens from the utility highlighting the problem in more detail here: http://imgur.com/a/EQPkC

Answer 1

Well, I've managed to fix the problem. No idea exactly what caused it in the first place, but the solution is to use AMD's RAIDXpert software which will allow you to simply "rebuild" the RAID array (which was a single button click and took around 30-45 minutes for my array).

The process, you are warned, will delete all data from the drive that had become unassigned from the array, and rebuild it with data from the drive that is still part of the array. Once this process was completed, my RAID Array was configured and functioning perfectly once again.

The difficulty in this is acquiring the AMD RAIDXpert software, usually available direct from AMD's website, this software has a habit of continually being removed and re-added, only to be removed again from their website. As of this writing (16th Jan 2015), the software is currently unavailable from the AMD website, but emailing AMD support directly and asking nicely might get you a copy. Alternatively, you could take a look here.