Public bug reported: Because EFI does not support instantaneous read of modifier keys (i.e. holding down shift at boot), the only way to reliably show a boot menu is by letting the system boot, interrupting the boot, and letting the menu be displayed because 'recordfail' has been set.
If /boot/grub is on LVM, recordfail does not work, because grub doesn't have write support on LVM, so saveenv doesn't work. Indeed, from the grub.cfg on such a system, the recordfail function is written as: function recordfail { set recordfail=1 # GRUB lacks write support for lvm, so recordfail support is disabled. } The interaction of these two limitations means that systems with /boot/grub on LVM cannot reliably get a grub menu, ever. While I think that in the long term we should always put /boot/grub on the ESP (which means it will always be writable by grub), which is in fact what we did for Ubuntu Core, in the meantime I believe what we need to do here is always show the boot menu if we are booted under EFI and we have a non-writable grubenv. ** Affects: grub2 (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1800722 Title: EFI booting + /boot on LVM == inaccessible boot menu To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/1800722/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs