On 2022-05-31 16:18:42 Felix Miata wrote:
J Leslie Turriff composed on 2022-05-31 15:23 (UTC-0500):
I've been using an EFI (not UEFI) system for years to run OpenSuSE Linux (since I have no Windoze on my machine I saw no reason to fool with UEFI, which had teething problems when I got my motherboard). Now I'm trying to install Ubuntu 20 LTS on a separate drive, but the installer is complaining about EFI and boot partitions. I've searched for help, but all I get is UEFI stuff. I don't want to reset my BIOS because then I wouldn't be able to boot back to my old system if I have problems with Ubuntu. Is anyone here interested in giving me a helping hand?
It's possible to have a UEFI on one disk and MBR/Legacy on another, but you'd have to manually construct required stanzas to enable booting one type from the other type. That's no problem at if you don't mind booting from the PC's BBS menu whenever you wish to boot from the other disk. Also, other can be added to current and vice versa manually by constructing /boot/grub2/custom.cfg and/or editing one of nn_CUSTOM in /etc/grub.d/. I've never actually tried booting UEFI Linux from Legacy Grub, but I have booted Legacy Linux from UEFI Grub. I never spent much time marrying Legacy with UEFI, because it's so much simpler just to get used to using the BBS hotkey when needed.
What could possibly be different about the basics between EFI and UEFI I've never pondered, other than without U it would be older and thus less well developed than newer versions.
"older" == "mature" :-D
I have 8 UEFI PCs including 1 Mac. All but the first are booting UEFI. UEFI is more sophisticated and IMO a vast improvement. Its different, but in this case different is better. My first that isn't using UEFI was my first exposure to UEFI, and an upgrade that included moving 3 disks with RAID1 on 2 of them, so I was only interested in quick success, not learning RAID in a UEFI context at the same time as learning UEFI.
That's basically the way I started; and there was a lot of FUD about most UEFI partition being too small for Linux but nothing much about sizing it right, so I just stuck with EFI.
IIRC, I have only one out of 30+ working multi- multiboot PCs on which Ubuntu is installed other than on an only disk. One OS installation per disk I never do.
I have just one PC and one ancient Mac. This is my first time trying multiboot. I can get as far as the partitioning step in Ubuntu install, but I want separate /opt and /usr/local partitions, so I can't just use the default single partition install. The installer says I need
IMO, your best way forward, subject to any EFI limitations imposed by your PC, is to install Ubuntu in EFI mode, then at some point in time convert the openSUSE installation to EFI mode.
Leslie --