earlier today, I upgraded my workstation in the office from Leap 15.2 to
15.3 with "zypper dup". Unlike my workstation at home where the upgrade
worked nicely, this machine failed to boot after the upgrade; I ended up
with "give root password for maintenance" prompt and while things looked
fine and most filesystems mounted, an attempt to setup networking failed
due to missing D-Bus.
After some experiments, I learned that the boot succeeds completely with
leftover 15.2 kernel which hinted me to check if kernel-default-extra
and kernel-default-optional are installed. They were not and installing
them resolved the issue.
After a successful boot, I checked loaded modules and found two which
were not in kernel-default:
jfs (JFS filesystem)
sp5100_tco (TCO timer driver for SP5100/SB800 chipset)
As I'm remote again, I don't want to confirm it with an experiment but
my prime suspect is jfs module as the machine has one JFS filesystem
mounted by default for historical reasons. Also, the sp5100_tco module
has refcount of zero.
But it does not really matter which module was missing, the important
question is: is this outcome expected? It is IMHO rather unfortunate if
a system fails to boot after an upgrade due to a missing kernel
subpackage. So perhaps even more important question: can we do something