| Can't really speak as to issues with single-OS installs. Those usually go alright. The problems I always run into arise when you try to go and install another OS alongside what you've already got (usually Windows, but I have seen the same kinds of UEFI issues with OS X+Linux and OS X+Windows+Linux). With legacy boot, this is relatively easy and goes something like this: 1) Resize existing filesystem, setup new partitions 2) New OS installation 3) Install GRUB over MBR 4) Boot whatever you want. Enjoy your multi-OS computer. Install more operating systems, whatever. GRUB has everything it needs to figure it out and edit /boot accordingly. With UEFI, it goes like this: 1) Resize existing filesystem, setup new partitions 2) New OS installation 3) Install GRUB2 over MBR 4) Realize you can't boot into new OS because of UEFI's "next boot" flag used by Windows 8+'s Fastboot/Fast startup option. 5) Realize you can't get into old OS either because secureboot is still broken for multi-OS environments. 6) Mess around with Windows Recovery Essentials. or an OS X Recovery System. Restore original boot sector with bootrec/Disk Utilities. Disable fast startup in BIOS. 7) Hopefully boot back into windows again. Sometimes the original Windows installation doesn't like the altered UEFI settings and you can't. When that happens I resort to re-installing each OS to separate hard disks, each with other OS' drive disconnected during installation. Then add another disk for GRUB2. Re-do GRUB2 probing/installation.
Then... 8) Disable fastboot in windows, cause UEFI is dumb and will let windows turn it back on. Probably mess around in bcdedit. 9) Load linux installation media again. Redo GRUB2 OS probing and installation, unless they're all fresh installs from step 7. 10) Hope everything works right at this point. 11) Wait for updates for your original OS to break everything, permanently lock you into booting just the original OS because of the terrible idea that was nextboot. If everything's on separate drives, you might be able to boot them independently from BIOS, and just have to disable settings again. Or not, because of the same "hey, this is a different computer, I'm not going to boot" type of stuff that can arise in 7. 12) Start again at step 4... |