Hello Hugga, thanks for joining the Intel Community.
Regarding the issue you are experiencing please check the following article Pag26
Degraded RAID 1 volume will not rebuild after failed hard drive is replaced
Make sure the "new" hard drive you are using is working or is in good condition. In addition, please make sure it has enough space so you can rebuild the RAID.
I appreciate the comments but there is nothing new I haven't already checked.
As I mentioned the disk is exactly the same model as the one replaced and of the drive still in service. The drive is also detected happily in Windows and by the controller and no SMART error has been flagged by the Matrix Console software.
The PDF document only discusses how to manually rebuild since the array does not autobuild after disk replacement. It makes no mention of the error message or the requirements of a "blank" disk.
I appreciate the software is trying to protect against accidental data loss, but to not give a means to force the removal of data is limiting. Surely it is documented by Intel as to what "system files" the test is checking for, and therefore an understanding as to what needs to be done to properly erase the disk for reuse.
Since I have used Killdisk, I expect the MBR has been erased and maybe I need to recreate it (maybe diskpart clean all) which i will try soon.
For some unknown reason, even though it was exactly the same model drive, the LBA addressing reported slightly less blocks than the source disk, only by 0.01Mb. I found this out using the Seatools for DOS utility and compared the 2 disks looking for differences. I used the "Set Capacity To MAX Native" menu to reset this anomaly and the rebuild worked fine. I don't know what circumstances would have changed this previously but it did come from a different system so maybe something to do with the history of the disk. I am sure other manufacturer's low-level utilities have a similar option so worth checking if you get stuck with this error.
I am also sure that the MBR (track 0) needs to be removed, I think this was my problem last time. But be aware KillDisk for Windows erases the MBR and then writes a new one (as per the bottom of http://www.killdisk.com/erasedata_win.htm). I found a freeware CLI utility that works under Windows too, called MBRWizard that looks very powerful (http://firesage.com/mbrwizard.php?x=4) and used it to erase my Track 0. I could have used Seatools for DOS as well.
PS I ended up replacing my faulty DVD drive to use Seatools for DOS, but I may have been incorrect earlier about USB boot as I found settings in the BIOS for it.
Hope someone finds this article useful.