I have a dual booting desktop for some time.
- /dev/sda - SSD drive containing Windows
- /dev/sdb - SSD drive containing Ubuntu
- /dev/sdc - HDD drive with data for both OSes
Recently I switched the SSD drives from MBR to GPT and switched off the legacy modus in my BIOS, so it is UEFI now.
Since then, the GRUB disappeared and I cannot get it to install again.
First I tried the "regular" way of booting from live USB, chrooting into the system on /dev/sdb and running grub-install. This results in the error:
grub-install: warning: this GPT partition label contains no BIOS Boot Partition: embedding won't be possible grub-install: error: embedding is not possible, but this is required for cross-disk install
Installing it to /dev/sdb is possible but then, depending on which device gets boot priority, there is no choice in OS (so boot from sda and you boot directly to Windows, boot from sdb and you boot directly to Ubuntu).
Then I tried wiping /dev/sdb and reinstalling from a live USB, but upon completing the setup, I get an error that the grub cannot be installed. Not on sda, not on sdb. I does not help if I first boot into "Try Ubuntu" and update, it keeps failing on this step. I tried lvm and regular, I tried manually setting the devices partition actions and just letting the setup do this.
I tried repairing Windows boot before reinstalling but nothing changed (to be fair, Windows was booting alright, so there might not be much to repair). I tried all options of bootrec.exe, I tried bcdboot and I tried Startup Repair.
Any idea what else I can try?