I'm happy to see this report closed right away as exotic, but thought I'd
report anyway...

I'm used to run tumbleweed, for quite a few years and very happily, on
production machines (host + kvm virtual machines), using my own,
almost-nomodular kernel builds. On the host side, that includes initrds, built
the normal way with mkinitrd + dracut and no customization needed. Good.

Now I ran into an issue when, for a different reported issue, I got asked to
try + reproduce with actual tumbleweed kernel-default. So I installed that,
mkinitrd ran normally - and it failed to boot properly.

The system (host) where that happened, uses RAID1 (md raid) disks (and LVM on
top) for boot + root.

What I found is that mkinitrd, apparently because the currently running kernel
(my own) has MD drivers built in (not loaded as modules), fails to include the
drivers/md modules into the initrd.

If I change "instmods '=drivers/md'" to "hostonly='' instmods '=drivers/md'",
in 90mdraid/module-setup.sh, I get it to include the modules + get a working
boot.

If I revert that change + rebuild the initrd again while the suse
kernel-default is running (with raid1.ko in lsmod), again I get a working
initrd with the modules included.

Hope this report helps someone who may stumble across the same issue, even if
no change results from it.