Blog O’ Matty

Monitoring Linux server performance with nmon

I recently came across Nigel’s monitor (nmon), which is an awesome text-based tool for visualizing a variety of CPU, memory, network and kernel performance data on Linux hosts. Nmon can be be run the without any arguments to display a base screen with CPU performance counters, or you can export the NMON environment variable with a list of performance counters you want displayed (you can also enable additional performance counters by typing the key that corresponds to the counter in the nmon display):

$ export NMON=cnDVk

$ ./nmon_x86_fedora5

Once nmon fires up, you will be greeted with a screen similar to the following:

Nmon performance monitor

Nmon is a great piece of software, and I am hopeful more distributions will include it in the future.

matty on June 6, 2007 | Filed Under Linux Utilities

6 Comments

Maxim Yegorushkin on June 7th, 2007

Awesome tool, thanks for sharing.

p.s. the tool homepage link seems to be broken

elip on June 11th, 2007

Looks almost exactly like systat from the BSD’s…was wondering if something like systat existed for Linux…wish it was a native tool on most distributions.

Sudhir on June 13th, 2007

Can you share the download link for this tool? The page that describes the tool is there on IBM’s website but the download link is not working.

Demosthenex on August 5th, 2007

The best part is saving nmon data to files, and processing them at need with the nmon analyzer (yes, its Excel). The amount of detail is fantastic!

Mark Seger on December 15th, 2007

Actually this reminds me a lot of a tool I wrote called collectl. The one neat thing about collectl is you can control the format of the output, showing everything in a lot of detail like nmon that I call ‘verbose’ more, OR have things line up horizontally to make it easy to see at a glance what’s going on. I also try to include as much data as I can think of, including Infiniband, nfs, sockets, lustre and more. collectl can also save save data in mulitple formats, including one that you can load into excel and another in rrd format.

http://collectl.sourceforge.net/index.html

-mark