MP 1,1-5,1 Un-bless EFI partitions on other drives?

[jfreberg]

My MacPro 5,1 (flashed from 4,1) is having trouble booting when there is a second drive connected that has OpenCore installed.

My primary boot drive is a PCI NVME SSD, and boots reliably with 2 other SATA drives in the system. I cloned the NVME SSD to a third drive as a safety backup. When that backup drive is installed, the system hangs on booting and never gets to the boot picker screen.

Removing the cloned drive allows the system to reboot normallly.

I suspect there is some kind conflict between the primary boot drive and cloned backup. Do I need to "un-Bless" the EFI partition on the cloned backup drive? If yes, how do I un-bless an EFI partition?

I have tested this with a SATA SSD drive and a conventional spinning drive. The results are the same with both drives. Disk Utility shows no problems with either drive.

Any ideas?

 

[Dayo]

Do I need to "un-Bless" the EFI partition on the cloned backup drive? If yes, how do I un-bless an EFI partition?

You un-bless by blessing something else.

What is happening in your case is that you actually do not have anything blessed and the firmware uses the first ESP it finds, which happens to be the unwanted one when that disk is connected.

You need to boot in without that disk connected and actually bless the wanted item to always be used ... until you unset things again.