Ever login to a Debian/Ubuntu system that just says the servername or something similar, but not the number of updates (if any) it needs? Normally when you login …you might see the message like this:
Welcome to Ubuntu 12.04.4 LTS (GNU/Linux 3.2.0-58-generic x86_64)
* Documentation: https://help.ubuntu.com/
115 packages can be updated.
115 updates are security updates.
Thats the message of the day (motd) modified or missing. Check if the file /etc/motd is existing and has content. When typing:
cat /etc/motd
Probably that file is empty in your case. The following packages need to be installed that the file is updated periodically:
base-files
update-notifier-common
You can force recreation of the file with this command:
sudo run-parts /etc/update-motd.d/
I’ve seen where that really doesn’t solve anything, and have to do this instead:
sudo /usr/lib/update-notifier/update-motd-updates-available