How do I monitor system performance using nmon?

nmon is a free console-based performance monitoring tool from IBM. It works on both AIX and RHEL.

If nmon is not already installed, you must first install it:

To use nmon:

View a step-by-step screencast of this process:
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  • Log into your server as root using a terminal emulator such as PuTTy (see also: How do I use PuTTy with my Eclipse server?)
  • (AIX only) Set the terminal emulation type to match the PuTTy console:
    export TERM=xterm
  • Run:
  • Press the appropriate keys to launch or close various monitoring windows. Type “h” for help. Here are some common views:
    • “t”: display top processes
    • “t” then”u”: display top processes by CPU utilization and show command line arguments
    • “c”: display CPU utilization
    • “l”: display longer-term CPU utilization averages
    • “d”: display disk I/O graphs
    • “h”: display help