Pertinent to this question I just asked Find files taking up 80% of the space on a Linux Webserver
I think a programme like this would be excellent. Up to date info about files & folders on the system and what space they were taking.
You could even throw in some warning info about permissions.
Does something like this exist?
I keep thinking of the windows app Treesize which I used back in '98 days.
It's unix, so you answered your own question: use cron to run a du command and write the output to a file.
For instance:
root@zachs:~# cat /etc/cron.d/update-home-sizes
0 4 * * * root du /home/* --max-depth 1 | sort -n >/home/.sizes
keeps a .sizes file in /home updated with how much disk each of my users is using. Tweak to suit your individual needs, of course.
You might be interested in agedu. From the description "It does basically the same sort of disk scan as du, but it also records the last-access times of everything it scans. Then it builds an index that lets it efficiently generate reports giving a summary of the results for each subdirectory, and then it produces those reports on demand. "
It will also supply a url which you can use to navigate your file system such that the age of the files in each directory is obvious.
ncdu is a curses interface to du. It's not so good for the batchness you want, but it'll show you what's using the space.
