Tag Archives: collectl

Pimp my collectl-advanced system monitoring using collect-utils part I

I have recently written about collectl, a truly superb troubleshooting utility, in a previous post. After comments from Mark Seeger (the author) and Kevin Closson (who has used it extensively and really loves it), I have decided to elaborate a bit more about what you can do with collectl.

Even though it’s hard to believe, collectl’s functionality can be extended by using the collectl-utilities from sourceforge, available here: http://collectl-utils.sourceforge.net/

Like collectl, you can either download a source tgz file or a noarch-RPM. Collectl-utils consist of three major tools, out of which I’d like to introduce the first one: colplot. When finding time I’ll create a post about the other part, most likely about colmux first.


I mentioned in said previous post that you can use the “-P” option to generate output in a plot format. This in turn can be fed to your favourite spreadsheet application, or alternatively into gnuplot. When chosing to use a spreadsheet application, it’s your responsibility to decide what to do with the raw data, each time you load a plotfile. Maybe, one day I’ll write a collectl-analyzer which does similar things to nmon-analyzer, but that has to wait for now. So if you are lazy like me, you need another alternative, and it comes easily accessible in the form of gnuplot. Continue reading

An introduction to collectl

Some of you may have seen on twitter that I was working on understanding collectl. So why did I start with this? First of all, I was after a tool that records a lot of information on a Linux box. It can also play information back, but this is out of scope of this introduction.

In the past I have used nmon to do similar things, and still love it for what it does. Especially in conjunction with the nmon-analyzer, an Excel plug in it can create very impressive reports. How does collectl compare?

Getting collectl

Getting collectl is quite easy-get it from sourceforge: http://sourceforge.net/projects/collectl/

The project website including very good documentation is available from sourceforge as well, but uses a slightly different URL: http://collectl.sourceforge.net/

I suggest you get the archive-independent RPM and install it on your system. This is all you need to get started! The impatient could type “collectl” at the command prompt now to get some information. Let’s have a look at the output:

$ collectl
waiting for 1 second sample...
#cpu sys inter  ctxsw KBRead  Reads KBWrit Writes   KBIn  PktIn  KBOut  PktOut
1   0  1163  10496    113     14     18      4      8     55      5      19
0   0  1046  10544      0      0      2      3    164    195     30      60
0   0  1279  10603    144      9    746    148     20     67     11      19
3   0  1168  10615    144      9    414     69     14     69      5      20
1   0  1121  10416    362     28    225     19     11     71      8      35

The “ouch” has been caused by my CTRL-c to stop the execution.

Collectl is organised to work by subsystems, the standard option is to print CPU, disk and network subsystem, aggregated.

Continue reading