No bootloader loading

[mand0rk]

So I have a UEFI system with Windows 10 installed to an NVME M.2 drive, and Kubuntu on a SATA SSD. It installed, but to boot into anything other than Windows, I have to select it using an external bootloader on my USB. The SATA drive doesn't appear in the boot order in BIOS, just says UEFI drive. Any ideas? Booting like this is not ideal. Also sorry if this has already been addressed elsewhere, but my quick search didn't turn up anything. Thanks peeps!

[jlittle]

If you are willing to overwrite the Windows boot loader, and you should be, run grub-install to the M.2 drive. I suggest enabling the "OS prober" first, by editing /etc/default/grub, though I don't know if that's necessary with a dual boot with Windows. Then grub will start when booting from the M.2, and have an menu entry for starting Windows.

[Schwarzer Kater]

To determine the path to your (M2 - or SATA SSD, see PPS ) drive (for sudo grub-install /dev/… to install the GRUB boot loader to this drive as jlittle suggested) one could e.g. enter lsblk -f in the Konsole terminal emulator.

You might also have to create/correct the (UUID) entry for your /boot/efi in /etc/fstab.
The entry should look like:

# /boot/efi was on /dev/yyyyyy during installation
UUID=xxxx-xxxx /boot/efi vfat umask=0077 0 1

where "xxxx-xxxx" is the UUID of your EFI partition and "yyyyyy" is the path to your EFI partition (the latter is not that important in this case as it is purely an information for yourself in a comment line).
Best to make a backup of this system file before changing it: sudo cp /etc/fstab /etc/fstab.orig .

You can edit /etc/fstab either in the Kate text editor or in Konsole with a CLI text editor like nano or vim if need be.

Feel free to ask if you need any more assistance.


PS: To make sure os-prober is enabled to find other systems (like Windows) and show them in the boot loader list you might have to edit /etc/default/grub .

Just add the lines

# Scan for other operating systems
GRUB_DISABLE_OS_PROBER=false

at the end, save the file and run sudo update-grub .
I suggest also making a backup first with sudo cp /etc/default/grub /etc/default/grub.orig .


PPS: IMHO the best (safest) solution to dual-boot with systems - if two different drives are available - is to have an individual EFI partition on each drive for the corresponding system.
So in your case one would leave the Windows drive (M2) completely alone, create a seperate EFI partion on the SATA SSD for Kubuntu (and at least a root partition, of course - and personally I would also use a seperate swap partition like the kernel developers still suggest), and point /boot/efi to the EFI partion of the SATA SSD in /etc/fstab - and also install GRUB to this drive.
After you have done all of the above one would then change the boot order in UEFI to boot from the SATA SSD first which will show the GRUB menu with entries for both Kubuntu and Windows.
And whatever Windows or Kubuntu will change in their EFI partitions in the future will then not directly effect the other system (also in case something goes wrong or you have to/want to reinstall Windows e.g.).

[mand0rk]

Thanks guys, I'll try that later today. I've been away from Linux too long. I feel like a noob again lol.

[mand0rk]

Suddenly both bootloaders I've tried using (GRUB2 and reFind) are now showing up in BIOS. Since they're all installed, I decided to keep all of them and go in order: GRUB, reFind, Windows Bootloader. If GRUB fails I have reFind, and if both fail I have Windows.