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MRTG-RRD(1)			     mrtg			   MRTG-RRD(1)

       mrtg-rrd - How to use RRDtool with MRTG

       After using MRTG for some time you may find some limitations, mostly in
       the areas of performance and graphing flexibility. These are exactly
       the areas addressed by RRDtool. To learn more about RRDtool check out
       its website on


       When using mrtg with RRDtool you are replacing rateup with the RRDtool
       perl module RRDs.pm. To enable RRDtool support in mrtg you have to add
       the line

	LogFormat: rrdtool

       to your mrtg config file.

       MRTG needs access to both the RRDtool perl module RRDs.pm and to the
       rrdtool executable.

       If these two items are not installed in locations where perl can find
       them on its own, then you can use the following two parameters to sup
       ply the appropriate directories.

       For the location of the rrdtool executable you put

	PathAdd: /usr/local/rrdtool/bin/


	PathAdd: c:\rrdtool\bin

       For the location of the perl module it would be:

	LibAdd: /usr/local/rrdtool/lib/perl/


	LibAdd: c:\rrdtool\bin\lib\perl

       When you have made this modification to the configuration file, several
       things will happen when you run mrtg again with the new config file:

       1.  mrtg will take all your old ".log" files and convert them to ".rrd"
	   format. (The ".log" files dont get touched in the process, so if
	   things dont work out they are still there.)

       2.  mrtg will use rrdtool to update its databases. These will have a
	   new format called rrd which is totally different than the native
	   log format of the classic mrtg.

       3.  mrtg will not create any webpages of graphs anymore.  It will only
	   query the routers for traffic information and update its rrd

       The advantage of whole thing is that the mrtg will become much faster.
       Expect the runtime to drop to 20% of the previous value. (I would like
       to get some feedback on this from folks with large installations.)

       Mind you, though, while the logging process of RRDtool is very fast,
       you are also gaining some time by neither creating graphs nor updating
       webpages.  The idea behind this is that it is more efficient to create
       graphs and webpages on demand by using a cgi script.

       At the moment there is no official script to do this, but two con
       tributers have created such scripts:

       One4All aka 14all.cgi
	   This was the first program to take over the webpage creation and
	   graphing task.  It has been developed by Rainer Bawidamann
	   rainer.bawidamann@web.de. You can find a copy on Rainers website:
	   http://my14all.sourceforge.net/ The program comes with its own doc

       routers.cgi, servers.cgi and generic.cgi
	   These are other cgi frontends to mrtg running with rrdtool. The
	   main difference between this and 14all is that the web pages it
	   creates are much more stylish than the ones from mrtg. These tools
	   have been written by Steve Shipway steve@steveshipway.org. You can
	   find a copy in http://www.steveshipway.org/software/ The programs
	   come with their own installation instructions.

	   The mrtg-rrd script is a CGI/FastCGI application by Jan "Yenya"
	   Kasprzak for displaying MRTG graphs from data in the RRDtool for
	   mat. It is an intended replacement for the 14all.cgi script. It can
	   make your monitoring system faster because MRTG does not have to
	   generate all the PNG files with graphs every 5 minutes or so.
	   Instead of this the graphs are generated on-demand when the user
	   wants to see them. http://www.fi.muni.cz/~kas/mrtg-rrd/

       Paul C. Williamson has written a more in-depth page on how the whole
       process works, including some performance figures. You can find his
       page on http://www.geocities.com/paulcwilliamson/mrtg/rateup2rrd.html

       Just as a side note: MRTG-3 will be based entirely on rrdtool technol
       ogy.  But dont wait for it ... get going now!

       Tobias Oetiker 

2.14.7				  2006-09-06			   MRTG-RRD(1)

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