Question RAID 5 replace drive, cannot rebuild array

Sep 10, 2021
RAID 5 replaced failed drive, now cannot rebuild array
ASUS Z390-a mb with 4 2Tb drives in RAID 5 array, has worked wonderfully for the past two years.

I had a failure where I could not boot into Windows or my Win10 setup rescue USB. I could only get into BIOS and then noticed one of the 4 drives in my array had failed. Because I could not boot the system with it in, I removed all the drives to find the damaged one, put the good 3 back in and put in a new RAID WD 2Tb drive to make the RAID array complete again and begin the rebuild. Btw, I probably do not have the drives back on the same satas because I disconnected all six during my troubleshooting.

Nothing happened though except that I could once again boot back into my Windows 10 OS. Once in, Disk Management popped up the new drive and I was told by the drive seller to initiate the new drive as GPT which I did. It shows up in Disk Management, but the other 3/4 drives do not show up, nor do they show up in Windows Explorer.

In my BIOS, my 3/4 RAID drives are recognized and in good shape, my SSD boot C drive and my ATAPI CD show up along with the newly added replacement RAID drive, so everything is recognized, the new drive just hasn't been accepted into the RAID array. Under the Intel RAID area, I have the option to delete my existing 3/4 RAID array or create a new RAID array with the non allocated disks, no options to rebuild with the new drive.
In the Intel Optane Memory and Storage Management win10 app, other than creating a new RAID array with the remaining drives (incl the new 2Tb I just dropped in), I can delete the 3/4 disk array or mark my new replacement drive as a spare, pretty hobbled app, no apparent options to rebuild the existing array.

Can anyone tell me what I am missing. My ASUS manual gives one page to describing RAID but nothing further. I have always diligently flashed by BIOS and it is up to date. A prior version of my mb Z370-a allows a Ctrl I at bootup to enter the RAID screen (like another BIOS screen), this mb does not, nor does Ctrl I work.

Any assistance greatly appreciated. I have asked vendors and IT techs to no avail, but they didn't get the volume of info I have provided here.

Thank you


You probably need to erase the drive and let the raid controller "see" it as not being used and make it available as a spare drive to rebuild with.

How you initiate the rebuild will depend on how you created the array , either in the bios (crtl+i) or in windows (rapid storage), and Which OS (Win10?)
Since it looks like the bios option is out, Rapid storage is where to head to. Its something like "rebuild to another disk, <select disk>, click Rebuild.