The mdadm-notify script is a little program that handles displaying notifications from mdadm --monitor by using the desktop notification system. To do so you have to have the notify-send binary available in your path, which usually comes with libnotify as well as a few other basic utilities that are documented in the script (they should be readily available on most Linux distributions as part of the base installation).

It handles the following notifications (from mdadm(8)):

All messages that are critical will never expire and thus require explicit interaction to dismiss them. All other messages have a timeout of 3 seconds, so the overlay will disappear but you can still find them in the notification area in case you missed them.

• Put the script somewhere, ensure it's owned by root and executable
• Set the PROGRAM option in mdadm.conf to point to this script
• (Re)start the mdadm or mdmonitor service

Sit back and relax, you'll see notifications pop up like: