No, I don't yet. I'm running myD: as the RAID1. The SiI Management s/w is showing both drives in yellow. However, I have a bootable Seagate diag which I ran once years ago which I try to us to make that determination. Do you have a better way? I also thought I could try easter-egging it by removing one drive and see what happens. If I can still access D: I've pulled the bad one, otherwise I'll try it again with the other drive.