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I have 2 hard disks — a 240 GB SSD and a 2 TB standard disk. I put Windows, Linux Mint, and Ubuntu 16.04 on the SSD, the sda and Fedora and Kali Linux on the 2 TB disk, sdb.

Now, as I was installing the systems (I installed them in the order Windows, Linux Mint, Ubuntu, Fedora and Kali Linux) until I exhausted the space in sda while installing Ubuntu, the grub menu kept changing as per the latest OS installed. Meaning, when I was done installing Linux Mint, Mint's grub2 menu had showed up during PC boot, and likewise, after I followed it up with Ubuntu's installation, Ubuntu's grub2 showed up. Now, I proceeded to install Fedora, followed by Kali Linux. But this time around, I see that same Ubuntu grub2 menu is being displayed. Also, in order to select Fedora or Kali, I need to press my boot options key F11 (MSI motherboard), where it shows Fedora and Kali. If I select and proceed with either, I'm able to boot to the respective system.

Tinkering around in Ubuntu, I tried the following:

sudo os-prober
sudo update-grub

These commands did the job and added Fedora and Kali to the Ubuntu's grub2 menu.

Now, I would like to know:

  1. Why has Ubuntu's grub2 assumed the role of native bootloader?
  2. How to make any grub2 menu as the native bootloader in cases similar to mine, i.e, when multiple Linux distros and/or multiple hard disks are involved?
mchid
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skrowten_hermit
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1 Answers1

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You installed Fedora and Kali Linux on the 2 TB disk, sdb, and you installed their bootloaders to sdb too. If you had installed their bootloaders to sda,they would have been used as default bootloaders, because the computer boots from sda by default.

It is possible to install a bootloader afterwards, 'repair grub'. See these links,

help.ubuntu.com/community/Grub2/Installing

help.ubuntu.com/community/Boot-Repair

The method you used with

sudo update-grub

is a good method, and should also be used, when 'the other' linux operating systems have upgraded (new) kernels. Otherwise these new kernels will not be available via the grub menu.

sudodus
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  • Okay. Kinda understand now. Sorry, could you clarify a bit more on that? So, does that mean I need to create the EFI system partition for Fedora and Kali on the SSD instead of the 2 TB hard disk by overwriting the EFI partition I had created for Ubuntu on SSD to make either of these system's grub the default bootloader? Or as mentioned in the links above the command sudo grub-install /dev/sda would take care of the situation? – skrowten_hermit Jan 11 '17 at 08:30
  • If you can boot all the installed operating systems from the current grub menu - fine :-) The only thing to do is to keep it up to date with sudo update-grub. If you prefer to boot from another distro, you should check for that distro, how it works, and make sure that it's boot menu will see all the other installed operating systems. Things are a bit complicated with UEFI, and some distros might have problems with it, for example when installed to another drive (not the first boot drive, /dev/sda). It is a good idea to back up your system or at least all important data before trying. – sudodus Jan 11 '17 at 08:41