My RAID-0+1 (2 sets of RAID-0 2TB HDD's) just failed with two drives failing, both drives being from each stripe. The worst case scenario. The Intel RAID utility could not recover the array. I went and then downloaded some utilities to try and recreate the array but they all couldn't determine what the array's configuration was that I setup. Time to read up on Microsoft's clustering file shares.
SO I went ahead and recreated the array using defaults and then tried the tool "TestDisk". TestDisk recognized my previous partition (which was GPT -- Wow!). I had to manually set the type to NTFS then the tool could let me see the files within. I pulled out about 900GB of Hyper-V VHD's and each one works perfectly. I am going to try recreating the partitions with that tool, but it's telling me that the disk is too small, the previous partition is 4000MB and the current partition is 3800MB. This maybe accurate because the Intel RAID utility tries to reserve 5% at the end of the array for expansion/drives of different sizes so they can be added to the array. Once the recovery of the VHD's completes, I will recreate the array with a slightly larger size then use TestDisk to recover the partitions and update it here if it worked or not.
UPDATE: I was not able to recover the partitions but I was able to recover the files successfully.