We have to migrate our existing hosts to UEFI.
Also, new hosts should be installed with UEFI.

During the migration, we have to maintain two lines on preseed with the appropiated recipes.
For UEFI:
To keep /srv: reuse-db-efi.cfg: https://github.com/wikimedia/operations-puppet/blob/production/modules/profile/data/profile/installserver/preseed.yaml#L228
To fully erase a host: db-efi.cfg https://github.com/wikimedia/operations-puppet/blob/production/modules/profile/data/profile/installserver/preseed.yaml#L215

In order to migrate an existing host to UEFI we have to add the following flag to the reimage process (https://wikitech.wikimedia.org/wiki/UEFI_Boot#Workflow):

--no-switch --no-users --no-dhcp

Query to see which hosts have been migrated:

sudo cumin 'A:uefi-boot and A:db-all'

To check which hosts are pending to be migrated:

sudo cumin 'A:bios-boot and A:db-all'