Sysadmin Challenge - Disk Usage

Here’s one for the sysadmins in the crowd; if you were asked to show the following how long would it take you to gather the information?

• Which of your file systems have the fastest growth rate?
• Which are the most under-utilised?
• Which haven't changed by more than 5% over the last month?

If you use Nagios you can cheat and work out the full drive size from the free space and percentage used reported by the disk checks, but that’s… icky. You get bonus points for having prediction built in to your usage graphs.