So, trying to find some utility(ies) to give us statistical information on this thing.
For example, what files were created in the last 30, 60, 90 days, 6 months, etc. What are their sizes?
Something with sortable reports would be nice.
I know we can do some things with a variety of command line switches for ls and using du, but these don’t create quite the reports I’m looking for ... Do you know of any appropriate utilities off of the top?
You might look into Nagios. It more of a complete system monitoring tool than a file system auditing tool. But it has lots of plug-ins available for it.
find is your friend, it has a very flexible query language. Combined with ls you can gather all the information you want.
The following command will give you all the files changed in the last 90 days along with their size: find . -ctime -90 -exec ls -ks {} \;
Next, use GnuPlot to generate your reports.