Note: this is kind of follow-up of this post: https://superuser.com/questions/1318478/booting-nvme-drive-with-a-bootloader, but I decided to post here since I'm trying to install and boot Ubuntu.
Summary: I'm installing Ubuntu on a NVMe drive, on a mainboard that doesn't support NVMe boot. I'm doing this by:
- Having a SATA drive.
- Booting the installation pendrive in UEFI mode.
- Creating an EFI partition on the SATA drive.
- Installing the
/filesystem on the NVMe drive.
- Installing the boot loader on the SATA drive.
The system is correctly installed, but as it reboots, it goes in grub rescue, saying that the volume is unknown.
Note that as I create the main partition on the NVMe drive, the installer leaves 1 Mb of "free space" at the beginning, so I suspect that the true EFI boot partition goes there.