Please bear with me as I try to explain this problem fully.
I have a server running ESXi. It has a number of VMs and has been working. This server has an LSI RAID controller and had a single hard drive attached to this controller. I am allergic to non-redundant drives, so I added a second drive and, from the RAID controller's boot BIOS (pre-boot of the server itself) I created the mirror and had the controller "rebuild" the second drive, copying an image of the first drive over it. The controller did so and displays a single virtual volume (in its BIOS) as a RAID 1 volume comprised of the two physical disks.
At this point I would expect any server OS to see the single volume. However, ESXi, on boot, sees both physical hard disks (seemingly ignoring the controller's supposed configuration, which is strange to me), and since they both contain identical copies of the ESXi install, it purple-screens complaining about two identical UUIDs. When I bypass this error with the command-line boot option "overrideDuplicateImageDetection", ESXi boots from one of the two drives. vSphere shows both drives as physical drives mounted in the system.
I am relatively certain that the RAID card is maintaining the mirror. The second drive is not part of a datastore. I'd prefer ESXi see the mirror as the single logical volume the RAID card is supposedly offering, but I will settle for ESXi ignoring the second drive altogether.
Any ideas?
Thanks in advance for your assistance,
H.