dg1727
commented
7 years ago From https://forums.linuxmint.com/viewtopic.php?f=237&t=240383#p1283311
the machine boots the live-DVD as legacy, so the installer assumes a legacy boot system
So it seems that the LMDE installer already contains code that can install to an MBR-formatted drive. I think the installer should ask the user about MBR vs. GPT based on the hard drive that's being installed to, not the medium (USB stick or DVD) from which the installer was run.
I recently installed LMDE2 Cinnamon 64-bit, using the Jan. 2017 beta installer, and the installer required an EFI system partition (ESP).
Until then, the hard drive had used an MBR. The MBR partition table already had 3 primary partitions + an extended partition (that is, the primary partition table was full), and I didn't want to put any of the primary partitions into an extended partition, so to add an EFI system partition I decided to convert the hard drive to GPT.
Suggestion: If there isn't an EFI system partition on the selected boot drive, then check for whether that drive already has an MBR. If so, then explicitly suggest that the drive maybe should be converted from MBR to GPT so an EFI system partition can be added more easily, & say that conversion to GPT is an advanced operation that's outside the scope of the installer.
This would be for users who (a) have an MBR hard drive, and (b) can't just add an ESP right away because the MBR partition table is already full, and (c) are surprised that LMDE can't be installed in this situation (since generally in this case, the hard drive already contains an OS that could be installed without an ESP).