In Ubuntu, how to get email notifications about (software) RAID problems?

Add MAILADDR [email protected] to /etc/mdadm/mdadm.conf, then /etc/init.d/mdadm restart or it'll just start on next boot. There's also a munin plugin if you're running munin with email alerts.

I found a nice tip closely related to my question, and wanted to share it:

TomTheGeek: Pop up notification of software RAID problems in Ubuntu

It's not about email notifications, but as the blog post says, pop-up notifications (like in screenshot below) might be even better when we're talking about a workstation.

I'll summarise the main points here (in case that blog ever disappears). This uses notify-send, so you need to install notification-daemon package. Basically you add this in /etc/mdadm/mdadm.conf (along with MAILADDR):

# display local notification
PROGRAM /usr/sbin/mdadm-notify.sh

...and the mdadm-notify.sh script should be something like:

#!/bin/bash

#get dbus session
eval `dbus-launch --sh-syntax --exit-with-session`

#show alert
/usr/bin/notify-send -u critical -c device.error -i /usr/share/icons/Human/32x32/status/dialog-warning.png -t 0 "RAID Status" "<b>$2</b>: $1" -h int:x:1250 -h int:y:20