Storage Management

Hi Admins,

I notice that one of my disk-based systems has lots of files that 
seem to have been hanging around for a ages. One user had over 50GB 
of data in a folder and they have left over a year ago. 

I am sure there are both commercial and open source tools for 
managing disk space. I want to identify very old files like the ones 
above and mark them for archiving and hopefully have a reporting 
tools so I can show users how much they are hogging and what files 
have been around for a long time.

Does anyone have an recommendations on a tool that might help? I 
could do something creative with find and perl but I think there are 
better tools out there than anything I could do. Is this what they 
call storage resource management?

Thanx,
Dp.