Why live DVD or USB drive don't boot anymore in UEFI environment?


#1

Hi All,
I am experiencing a funny problem: as in the title, can’t boot anymore live DVD or USB flash drive on my desktop computer with 2 HDD (GPT-UEFI), one for Linux and one for Windows 10.
Can say that the last operation of mine has been installation of Mageia 6 AMD64 KDE, before that no problem to get live distro at boot. Now, nothing is on the boot list or flash drive is on legacy section (not UEFI) and does’nt boot.
(Linux-Mint 18.3, Debian 9, Mageia 6 /dev/sdb and Windows 10 /dev/sda. /boot-efi on /dev/sdb1).
Please, do anyone know how to solve the problem?


#2

First, I want to clarify something: usually GPT and UEFI go hand in hand but they are not the same, so I would refrain from saying that you have “GPT-UEFI” hard drives. Your hard drives have a GPT partition table, but your computer, the motherboard to be specific, has to support UEFI to make everything work in UEFI. Therefore I advise you to check your UEFI (which is what you probably incorrectly know as BIOS) for how it is set up in regards to legacy (BIOS) support.
Modern UEFIs usually have a CSM mode, which allows boot from MBR drives that are made to work with the BIOS. If you turn on CSM and restart the computer you should be able to see your live media again. Even though this option exists, I would highly recommend against actually using (i.e. booting media) CSM because it is broken and can cause many different issues when booting OSes through this.

So as a final solution I would recommend burning your live media on GPT-enabled devices, so you can use them in pure UEFI mode, instead of CSM mode. If an actual live DVD doesn’t work either, then this means that the burnt OS itself doesn’t have EFI support.

If you are burning the live OSes onto your USB drive within Windows, I would recommend using Rufus, because it specifically allows the drive to be formatted in clear GPT partition scheme, which is of course UEFI-enabled.


#3

Hi Akito,
Thank you for your kind concern, let me clarify something: I pointed out “GPT-UEFI” to give briefing on my machine (English is not my mother language but am sure you get me). After that, I repeat: the strange point is that the problem comes out with media already used on the same machine without any problem (same for SystemRescueCD), everything done from the same distro (Linux Mint 18.3). That’s why I don’t understand what is wrong, I suspect the last installation (Mageia) messed up something but don’t understand what, I don’t get any warning over all distros and Windows.
Can only add that on the new attempt of mine I get DVD too listed on the legacy section, not only USB pen.
Thank you once again, the issue is apparently weird for everyone, your answer is the first and unique received till now and searching online I don’t find any clue. Ciao


#4

Still, the issue as you described it should have something to do with your UEFI settings, which means that it shouldn’t have something to do with your Mageia installation. Are you sure that you didn’t change any of your UEFI settings or maybe upgraded it to a newer version?


#5

Yes Akito, I am sure; is weird, also efibootmanager output does’nt show nothing wrong


#6

Officially: Mageia’s installation was the source of the problem.
Steps:

  • Update GRUB from Mageia.
    Result = only Mageia and Windows on the boot list but only Windows booting even selecting Mageia. At the same time, live DVD booting.
  • Removed Mageia using Linux-Mint live DVD (GParted).
  • Reinstall GRUB (on Linux-Mint).
  • Cleaning boot list using efibootmanager.
    SOLVED

#7

Although I would not have a solution to your problem , I see that Mageia is an RPM distro ,whereas Linux Mint is based on Debian/Ubuntu e.g. DEB .
Can the 2 different package managers co-exist on the same Hard Drive ? …I don’t know.

Frank in County Wicklow - Ireland


#8

Yes, they are bound to their respective distributions. They don’t interfere with each other. Otherwise you also would have a problem with Windows and GNU/Linux, etc.


#9

If you can do try booting in legacy that sometimes works. I did it when I first installed Mint along side Windows 10 as I found that W10 dominated the start up. After I got rid of 10 I went back to UEFI and have had no problems with duel booting any linux since


#10

The emergency legacy support built into UEFI is another option, but it should only be used to fix the actual UEFI, as did you. There’s no point in having UEFI, if you only use the inferior mode for everything.