I have Mac, which means I have EFI and a GPT formatted disk with a hybrid MBR. I am considering adding a fifth partition; to do this, I will mask my first three GPT partitions with one partition in my protective and hybrid MBR.
However, if, say, I fire up an operating system after these (say, on my fourth I have Linux), will I be able to mount filesystems from inside the protective MBR? I.e., can an OS like Linux that has been booted from a legacy MBR view GPT partitions, or does it rely on the MBR to tell it what partitions exist?
mount rely on MBR, or will it find (my) GPT disks?
Full / Old Question
I have a hybrid MBR of 4 partitions on my Mac.
1. EFI System Partition 2. Mac OS X 3. Mac Recovery Partition 4. Ubuntu
Now, I want to add Archlinux to the end, i.e., append
5. Archlinux, but I would also like to maintain a reasonable MBR (because an MBR can only have four records).
My idea is to create a MBR partition that covers both partitions 1 and 2, or 2 and 3, or 1-3, thus making the MBR think that there is one partition, and nothing will touch it (this is typical of GPT disks, which have a protective MBR which covers all the GPT partitions with one legacy MBR partition for safety reasons).
My question is: Does Ubuntu use the MBR to mount filesystems? If I do create my nice protective partition, will I no longer be able to mount my Mac OS X filesystem in Ubuntu, assuming Ubuntu is installed using the legacy MBR method, and not the GPT / EFI boot Ubuntu.*
*Or maybe EFI compatibility in Ubuntu is better now?