If you install from the "minimal install" ISO you get a prompt near the end to enable automaigically applying security updates.
I usually elect for that option -- one of the other things that happens when you take that option is that you get a cute little login script that provides some interesting statistics along how many pending updates are available and if a restart is required. I find this mildy amusing, and other than the extra time it causes at login, never thught too much about it until I noticed this:

Welcome to Ubuntu 12.04.2 LTS (GNU/Linux 3.2.0-38-generic x86_64)

 * Documentation:  https://help.ubuntu.com/

  System information as of Sat Mar  9 11:29:28 CST 2013

  System load:  0.0                Processes:            98
  Usage of /:   0.8% of 450.20GB   Users logged in:      0
  Memory usage: 1%                 IP address for bond0: xxx.xxx.xxx.xxx
  Swap usage:   0%

  => /mnt/md0 is using 88.0% of 9.40TB

  Graph this data and manage this system at https://landscape.canonical.com/

0 packages can be updated.
0 updates are security updates.

Last login: Sat Mar  9 10:49:34 2013 from 

:~$ df
Filesystem       1K-blocks       Used Available Use% Mounted on
/dev/sda3        472069424    3686732 444402868   1% /
/dev/md0p1     10095015976 8879129108 703089336  93% /mnt/md0

:~$ df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/sda3       451G  3.6G  424G   1% /
/dev/md0p1      9.5T  8.3T  671G  93% /mnt/md0

After a certain utilization point on any given system the login descript displays a usage indicator regarding the level of utilization -- in this case the login script is squawking about 88% of /dev/md0p1 being used.
runing 'df' or 'df -h' reveals utilization is actually a bit higher.

Not really a big deal, but it isn an interesting quirk. is this just the difference in calculating MiB vs MB?

Anyone have any experience with the set of packages that provide these login scripts? I know it's more than one package, as I tried to add it to a server without the option selected during installation.