Failover Cluster validation fails with the following error: “Failed to prepare storage for testing on node X status 87”:
This error was caused by how the operating system was installed on the server. For some reason there was a separate hidden boot partition with no name:
I suspect that this is the remains of a Dell OEM installation CD, as there is also an OEM partition on the drive. I didn’t install the OS on this server though, so I was unable to figure out exactly what had happened.
The solution is simple enough, just assign a drive letter to the boot partition:
You could also reinstall the node or create a valid boot loader on the C: drive, but just assigning a drive letter to the partition is way quicker.