Comment # 1 on bug 1206943 from Antonio Feijoo

First, I would recommend you to always use dracut and avoid mkinitrd, as it's
just an incomplete compatibility wrapper that internally calls dracut. It's
deprecated and will be removed very soon.

Next, about your issue. SUSE by default builds hostonly initrds
(/usr/lib/dracut/dracut.conf.d/01-dist.conf), adding to the them just what is
necessary to boot the running system.
As you pointed out, the mdraid module (like most of the dracut modules) only
installs kernel modules in use when the initrd is built in hostonly mode.

So, you have two options in your case:
- Add all the raid kernel modules by hand, using `add_drivers+=" =drivers/md "`
in a configuration file or the `--add-drivers " =drivers/md "` command line
option.
- Build a non-hostonly initrd (`hostonly=no` in conf or `-N` option).