This subfolder is dedicated to dracut related files.

The folder 'dnbd3-rootfs' is a dracut module used to setup
a client's rootfs based on a (read-only) dnbd3 export made writable
through the kernel device mapper features.

To use this module within dracut, you simply need to copy/link/mount
the above mentioned folder to '/usr/lib/dracut/modules.d' prefixed
with a numerical priority. We used '90' so far, so the module was linked
to '/usr/lib/dracut/modules.d/90dnbd3-rootfs'.

Once the module has been integrated in dracut's modules, you can build
the initramfs with the following command:

    dracut --no-hostonly --modules "dnbd3-rootfs" <target_path>

Note that the '--no-hostonly' is critical if the machine dracut is
executed on and the clients supposed to boot the resulting initramfs
differ.

For more informations see: https://lab.ks.uni-freiburg.de/projects/dracut-praktikum/wiki