$ sudo apt-get update
$ sudo apt-get install mdadm-udeb 

mdadm-udeb is installed in your system.

Make ensure the mdadm-udeb package were installed using the commands given below,

$ sudo dpkg-query -l | grep mdadm-udeb *

You will get with mdadm-udeb package name, version, architecture and description in a table

mdadm-udeb package basic information: