On Sun, 13 Mar 2016 at 01:49:19 -0500, Kenneth Westerback wrote: > The non-support for Hybrid MBRs was a deliberate choice and there are > no plans to open that can of worms. Hybrid MBRs are not part of the > GPT/UEFI standard as far as I can discover, and almost everything > Google turns up on the intertubes says DON'T DO IT!!
Well it was certainly not by choice, and any disk with a hybrid MBR like this could present a problem when installing to it because of our GPT/MBR heuristics. I'm not asking for hybrid MBR support, but rather to just choose to use the GPT data when there is a valid GPT label and at least one EE partition (regardless of size or partition count), ignoring the rest of the hybrid MBR data entirely. Since we have proper GPT support, we shouldn't ever need to muck with the MBR partitions of a disk with a hybrid MBR. > Not being a Mac OS X Disk Utility guru I can't say for sure but I can > read some of the docs as saying the Hybrid MBR is only created when > you create a DOS FAT partition. So my first suggestion would be to try > creating the new partition as something else like HFS+ and changing it > to A6 with GPT editing during install. I tested that on a USB disk and it does appear to create one big EE/protective partition when everything is HFS+, so I've updated my MacBook dual-boot guide to recommend that instead of MSDOS.