need instructions to install a bandwidth graph

I need a set of written instructions to install a bandwidth graph on an Apache Web server running on CentOS 4.x. It should be something that I can use to see bandwidth usage per day for the last 30 days, e.g.: On Jan 14, 300 megabytes transferred, on Jan 15, 250 megabytes transferred, etc. I tried cacti, but I couldn't use that at least with the default instructions, because it was so horrendously complicated to get it installed and to create the right graph, and there are large parts missing from the available documentation. Since I have to repeat this across 20 machines it has to be much simpler than that. I also tried mrtg but the only thing I could figure out how to do with that, was show the average bytes per second over the last day, last week, last month, etc. That's not what I need since I need to be able to see the total bytes transferred over a period of days. Now, it may be that there is a way to do what I want, using cacti or mrtg, but in that case I just need instructions on exactly what to do to set it up. Or, if there's another tool that will do it, I just need instructions on how to set that up instead. Thanks! ## Deliverables Instructions on how to set up a bandwidth graph meeting the requirements above. The instructions don't have to work the first time I try them, but please be available to answer questions if something doesn't work :) ## Platform All our servers are running CentOS 4.x.