=head1 NAME

mrtg-rrd - How to use RRDtool with MRTG

=head1 SYNOPSIS

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

 http://oss.oetiker.ch/rrdtool

=head1 RRDTOOL INTEGRATION

When using mrtg with RRDtool you are replacing F<rateup> with the

RRDtool perl module F<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 B<RRDs.pm> and to the

B<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 supply the

appropriate directories.

For the location of the B<rrdtool> executable you put

 PathAdd: /usr/local/rrdtool/bin/

or

 PathAdd: c:\rrdtool\bin

For the location of the perl module it would be:

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

or

 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:

=over

=item 1.

mrtg will take all your old C<.log> files and B<convert> them to C<.rrd>

format. (The C<.log> files don't get touched in the process, so if things

don't work out they are still there.)

=item 2.

mrtg will use B<rrdtool> to update its databases. These will have a new format

called I<rrd> which is totally different than the native I<log> format of

the classic mrtg.

=item 3.

mrtg will B<not> create any webpages of graphs anymore.

It will only query the routers for traffic information and update its I<rrd>

databases.

=back 

The advantage of whole thing is that the mrtg will become B<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 B<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 B<official> script to do this, but two

contributers have created such scripts:

=over

=item 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 documentation

=item B<routers2.cgi>

This is another CGI frontend for 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, plus they support User

Defined summary graphs and different levels of Authentication and Authorisation. This has been written by

Steve Shipway (steve@steveshipway.org). You obtain a copy, and find a forum and demonstration system at

http://www.steveshipway.org/software/

The program comes with its own installation instructions and install script.

=item B<mrtg-rrd>

The mrtg-rrd script is a CGI/FastCGI application by Jan "Yenya" Kasprzak for

displaying MRTG graphs from data in the RRDtool format. 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/

=back

=head1 FUTURE

Just as a side note: MRTG-3 will be based entirely on rrdtool technology.

But don't wait for it ... get going B<now>!

=head1 AUTHOR

Tobias Oetiker E<lt>tobi@oetiker.chE<gt>