Ubuntu
grub2 package

  1. Bug #1750732
  2. Comment #8

Comment 8 for bug 1750732

Revision history for this message
dann frazier (dannf) wrote :

The system was set to boot from PXE by default, at least before MAAS deployed it:
Feb 22 03:28:41 lodygin cloud-init[3447]: + echo before grub-install efiboot settings
Feb 22 03:28:41 lodygin cloud-init[3447]: before grub-install efiboot settings
Feb 22 03:28:41 lodygin cloud-init[3447]: + efibootmgr
Feb 22 03:28:41 lodygin cloud-init[3447]: BootCurrent: 0002
Feb 22 03:28:41 lodygin cloud-init[3447]: Timeout: 1 seconds
Feb 22 03:28:41 lodygin cloud-init[3447]: BootOrder: 0002,0003,0004
Feb 22 03:28:41 lodygin cloud-init[3447]: Boot0002* UEFI: IP4 Intel(R) Gigabit CT Desktop Adapter
Feb 22 03:28:41 lodygin cloud-init[3447]: Boot0003* UEFI: Built-in EFI Shell
Feb 22 03:28:41 lodygin cloud-init[3447]: Boot0004* Hard Drive

Now, curtin will install an entry and monkey with the boot order during deployment. I'm aware of a couple of firmware implementations where that breaks things - but I don't see signs of those known issues here. And, after deploy you say efibootmgr output looks correct - so that suggests nothing has gone wrong yet.

As @cyphermox mentioned, maas/curtin should be configuring the system to skip modifying NVRAM. And the debconf-get-selections output confirms this:

# Update NVRAM variables to automatically boot into Debian?
grub-efi-amd64 grub2/update_nvram boolean false
grub-pc grub2/update_nvram boolean false
grub2 grub2/update_nvram boolean false

This means efibootmgr output *should be* the same before and after you upgrade GRUB. Can you confirm that is true? Since you mention rebooting as step #4 in reproduction - that suggests the boot order breakage is occuring somewhere in firmware after reboot.

Regarding @cyphermox's point about shim fallback.... these days, curtin leaves the system with an Ubuntu entry, but makes it the 2nd option in the bootorder. The idea is that if MAAS is down for some reason, the system will fallback to booting from the disk (instead of failing to boot altogether). What would happen if PXE failed, and Ubuntu - as the 2nd priority boot option - started? Would shim fallback reorder the menu?