On screen (console, telnet, VNC, putty or X Windows) using curses for low CPU impact which is updated once every two seconds. You hit single characters on you keyboard to enable/disable the various sorts of data.
You can display the CPU, memory, network, disks (mini graphs or numbers), file systems, NFS, top processes, resources (Linux version & processors) and on Power micro-partition information.
For lots of examples, see the "Screen shots" from the left menu.
As you can see on the left lmon12e now in colour
Save the data to a comma separated file for analysis and longer term data capture.
Use this together with nmon Analyser Excel 2000 spreadsheet, which loads the nmon output file and automatically creates dozens of graphs ready for you to study or write performance reports.
Filter this data, add it to a rrd database (using an excellent freely available utility called rrdtool). This graphs the data to .gif or .png files plus generates the webpage .html file and you can then put the graphs directly on a website automatically on AIX with no need of a Windows based machine.
Directly put the data into a rrd database or other database for your own analysis
Install nmon in ubuntu
Open the terminal and run the following command
sudo apt-get install nmon