GRUB File Locations

Hello,

I was checking machine logs through the MAAS dashboard and saw a bunch of TFTP requests for GRUB files (as seen in the image below). I’m trying to find where these files are located, to figure out if my MAAS installation is still missing files and to also see exactly how MAAS is loading OSs.

What is the path of the /grub/grub.cfg-xx:xx:xx:xx:xx:xx and /grub/x86_64-efi/command.lst GRUB files in the controllers? Also, which controller is supposed to handle these files? The region controller or the rack controller?

I my region controller, I can’t find anything other than grubx64.efi and bootx64.efi files.

In my rack controller, I can only find grub.cfg at /var/snap/maas/common/maas/tftp_root/grub and that file loads /grub/grub.cfg-xx:xx:xx:xx:xx:xx or /grub/grub.cfg-default-<grub_cpu> , but I don’t know from where.

Where do I find the other GRUB cfg and lst files and on which controller (region or rack)?

Thank you!

PS: It would be good to have additional documentation on how MAAS boots OSs in addition to what is mentioned on the MAAS | About images page. If it exists and I missed it, my apologies. Please point me to that if possible. Thank you!

The response is generated on the fly by MAAS depending on what the machine should do. MAAS will generate the response picking a template that you can find here maas/src/provisioningserver/templates at master · canonical/maas · GitHub , but in order to understand what’s the logic behind you have to dig a bit into the code