On 02/05/2018 09:10 PM, Chris Murphy wrote:
On Mon, Feb 5, 2018 at 8:27 AM, Kay Diederichs kay.diederichs@uni-konstanz.de wrote:
grub-install /dev/nvme0n1
Running this on computers with UEFI firmware is not good advice, it's an obsolete command. People should use the prebaked grubx64.efi binary that comes in the grub2-efi package, and is a signed binary so it can support UEFI Secure Boot.
If you run grub2-install, a new unsigned grub binary is created, replacing grubx64.efi. If you have Secure Boot enabled, you will not be able to boot, until you either reinstall the grub2-efi package (or you self-sign the grub2-install created binary and then go through the process of informing the firmware this is a valid binary by using mokutil - but I estimate maybe 1 in 50 people might do this).
Did you read my sentence "I recovered my Ubuntu grub menu ..." and that this mentions grub-install, not grub2-install ? The procedure that I describe is correct for Ubuntu - see e.g. https://askubuntu.com/questions/831216/reinstalling-grub2-efi-partition https://help.ubuntu.com/community/Grub2/Installing#Boot_repair_after_a_Windo...
The important point of my posting was to tell the OP the reason and mechanism which leads to a loss of the grub menu. The OP already described how s/he got the machine to boot again.