Issues with triple boot Windows, Ubuntu & Manjaro | MBR & "/boot/efi" Partition

uefi
kde
mbr
ubuntu
windows-10

#1

Hello,

I have a laptop with three operating systems (Windows, Ubuntu 14.04, Ubuntu 16.04) installed in different partitions of a single hard drive along with extended partitions. Managed by GRUB2 boot loader on Ubuntu 16.04. Although, my laptop supports UEFI, I didn’t use it and I enabled CSM (Compatibility Support Module) in BIOS/UEFI.

Hard drive (sda) structure looks like this:
MBR: GRUB2
sda1 (Windows, NTFS, Primary)
sda2 (Ubuntu 14.04, EXT4, Primary)
sda3 (Ubuntu 16.04, EXT4, Primary)
sda4 (Extended Partition)
|_ sda4 (NTFS, Logical)
|_ sda5 (NTFS, Logical)
|_ sda6 (NTFS, Logical)

I wanted to reinstall the Windows OS and also to try Manjaro replacing one of the Ubuntu (14.04) Operating Systems. I followed the steps as below,

  1. Reinstalled the Windows OS by formatting the partition sda1. Now, the MBR is replaced by Windows boot loader and I couldn’t see any other operating system in the boot menu. I left it as it is, since I hoped, after I install Manjaro, the boot loader will eventually get replaced by GRUB2.

  2. I booted the Manjaro KDE (18.0.2) live USB and followed through the installation process. While on disk partition, I formatted the partition sda2 (Ubuntu 14.04) and selected it as “/” mount point.

  3. After few steps forward, I’ve been asked that I will need to create another “fat32” partition with “/boot/efi” as mount point or else I won’t be able to boot into the system. But, since I have utilized all the possible primary partitions on my hard drive, I could not create a new partition for “/boot/efi”. Anyway I formatted the Ubuntu 14.04 partition (sda2) and quit the installation setup.

  4. Now, I’ve “chroot” into my Ubuntu 16.04 in sda3 via live USB operating system and updated GRUB2 and reinstalled it in the hard drive again, replacing the Windows MBR.

  5. Now, I can see two operating systems in the boot menu Ubuntu 16.04 and Windows. Both of them boots and works properly.

Now, the hard drive (sda) structure looks like this:
MBR: GRUB2
sda1 (Windows, NTFS, Primary)
sda2 (Formatted and no operating system installed, EXT4, Primary)
sda3 (Ubuntu 16.04, EXT4, Primary)
sda4 (Extended Partition)
|_ sda4 (NTFS, Logical)
|_ sda5 (NTFS, Logical)
|_ sda6 (NTFS, Logical)

  1. Again, I booted up the Manjaro 18.0.2 Live USB and tried to install the OS again by selecting the partition I’ve previously formatted sda2 and used it as mount point “/” and followed through the installation process and now I didn’t see that warning message that requires to create the “/boot/efi” partition.

  2. After installation, I can see all three operating systems (Manjaro, Ubuntu 16.04 and Windows) in the boot menu and all of them boots and works well without any issues.

Now, the hard drive (sda) structure looks like this:
MBR: GRUB2 by Manjaro
sda1 (Windows, NTFS, Primary)
sda2 (Manjaro 18.0.2, EXT4, Primary)
sda3 (Ubuntu 16.04, EXT4, Primary)
sda4 (Extended Partition)
|_ sda4 (NTFS, Logical)
|_ sda5 (NTFS, Logical)
|_ sda6 (NTFS, Logical)

Could anyone clarify that, "How and Why this second installation worked with out asking for “/boot/efi” partition, compared to my previous try?"

The only difference I see is that on my first attempt Windows boot loader in MBR was active and on my second attempt Ubuntu 16.04 GRUB2 was in MBR. Is this has anything to do about the “/boot/efi” partition?


#2

In your first attempt to install Manjaro you had booted the installer ISO in UEFI mode. For a UEFI installation an $esp partition mounted at /boot/efi is required.
In your 2nd attempt you had booted the installer in (the proper for your setup) MSDOS/Legacy mode, which does not require $esp but installs grub at MBR.

Welcome to Manjaro!

Advice: Always use Manjaro grub for MBR (remember to not do grub-install from Ubuntu. When Ubuntu does a grub update, remember to boot to Manjaro and update grub.


#3

Thanks for the quick reply @petsam

Interesting. I haven’t noticed that I have changed that. I’ll go read the Manjaro wiki page for more info on this and verify once again.

Thanks lot for the advice. I will make sure to follow them. :smile: :+1:


#4

Or the OP can ‘set grub’ to its own partition (at Ubuntu terminal)

sudo grub-install --force /dev/sda3

ps: there will be a warning (something about ‘embedded’ and … something else) but it’s okay to proceed.


#5

There are several ways to achieve what you want in Linux :stuck_out_tongue_winking_eye:
Thanks Captain!!