mrtg-unix-guide - The MRTG 2.17.4 Linux/Unix Installation Guide
MRTG comes to you in Source Code. This means that you have to compile parts of
it before you can use it on a Unix machine. These instructions help you to do
In order to compile and use mrtg you need a C compiler and a copy of perl
installed on your machine. In most cases this will already be available. In
case it is not, here are some starting points. Below I'll give you a detailed
run through the whole compilation process.
- The GNU C compiler comes preinstalled on most of the free Unicies out
there. For commercial derivatives you may have to download and compile it
first. If you have no compiler at all there is a chicken and egg problem,
but there are also precompiled versions of gcc available for most
- Large parts of the MRTG system are written in the Perl scripting language.
Make sure there is a recent copy of perl on your machine (try perl -v). At
least version 5.005 is required for mrtg to work well. If you use SNMPV3
and other new features you should use at least 5.8.
You can get the latest perl from
MRTG generates traffic graphs in the PNG format. To be able to do this it needs
several 3rd party libraries. When compiling these libraries I urge you to make
sure you compile them as static
libraries. There is just much less
trouble ahead if you are doing it like this. See the Instructions in the next
section for inspiration. Note that many free unices have all the required
libraries already in place so there is no need to install another copy. To
check it is best to skip all the library instructions below and go straight
into the mrtg compile.
If the first attempt fails and you do not get a working version of mrtg, try
compiling new copies of all libraries as explained below. Do this
you send email to me about problems compiling mrtg.
- This is a basic graph drawing library created by Thomas Boutell. Note that
all releases after Version 1.3 only create PNG images. This is because a)
Thomas got into trouble because the GIF format which it used to produce
uses a compression technology patented by Unisys. b) PNG is more efficient
and patent free. MRTG can work with old and new version of the GD library.
You can get a recent copy of GD from:
- Is required by gd in order to produce PNG graphics files. Get it from:
- Is needed by libpng to compress the graphics files you create. Get a copy
And last but not least you also need mrtg itself. In case you have not yet
downloaded it, you can find a copy on my website:
In this section I will give you step by step instructions on how to compile the
various libraries required for the compilation of mrtg. Note that these
libraries may already be installed if you have a *BSD
system so you can skip recompiling them. The wget
program used below is
a simple web downloader. You can also enter the address into your
if you don't have wget
First let's create a directory for the compilation. Note that this may already
exist on your system. No problem, just use it.
mkdir -p /usr/local/src
If you do not have zlib installed:
gunzip -c zlib-*.tar.gz | tar xf -
mv zlib-* zlib
If you don't have libpng installed
gunzip -c libpng-1.2.34.tar.gz | tar xf -
mv libpng-* libpng
env CFLAGS="-O3 -fPIC" ./configure --prefix=$INSTALL_DIR
rm *.so.* *.so
And now you can compile gd
For versions up to 1.8.4, try:
gunzip -c gd-*.tar.gz |tar xf -
mv gd-* gd
The \ characters at the end of the following lines mean that all the following
material should actually be written on a single line.
perl -i~ -p -e s/gd_jpeg.o//g Makefile
make INCLUDEDIRS="-I. -I../zlib -I../libpng" \
LIBDIRS="-L../zlib -L. -L../libpng" \
LIBS="-lgd -lpng -lz -lm" \
For versions starting around 2.0.11, try:
gunzip -c gd-2.0.33.tar.gz |tar xf -
mv gd-2.0.33 gd
env CPPFLAGS="-I../zlib -I../libpng" LDFLAGS="-L../zlib -L../libpng" \
./configure --disable-shared --without-freetype --without-jpeg
cp .libs/* .
Ok, now everything is ready for the mrtg compilation.
gunzip -c mrtg-2.17.4.tar.gz | tar xvf -
If all the libraries have been preinstalled on your system you can configure
mrtg by doing a simple:
Otherwise you may have to give some hints on where to find the various libraries
required to compile mrtg:
./configure --prefix=/usr/local/mrtg-2 \
If you have RRDtool available you might want to tell mrtg about it so that you
can opt to use rrdtool with mrtg. Check mrtg-rrd.
Configure will make sure your environment is fit for building mrtg. If it finds
a problem, it will tell you so and it will also tell you what to do about it.
If everything is OK, you will end up with a custom Makefile for your system.
This builds the rateup binary and edits all the perl pathnames in the scripts.
You can now install mrtg by typing
make install (requires gnu install)
All the software required by MRTG is now installed under the
You can now safely delete the libraries we compiled above. Then again, you might
want to keep them around so that you have them available when compiling the
next version of mrtg.
The next step is to configure mrtg for monitoring a network device. This is done
by creating an mrtg.cfg
file which defines what you want to monitor.
Luckily, you don't have to dive straight in and start writing your own
configuration file all by yourself. Together with mrtg you also got a copy of
. This is a script you can point at a router of your choice; it
will create a mrtg configuration file for you. You can find the script in the
cfgmaker --global 'WorkDir: /home/httpd/mrtg' \
--global 'Options[_]: bits,growright' \
--output /home/mrtg/cfg/mrtg.cfg \
This example above will create an mrtg config file in /home/mrtg/cfg
assuming this is a directory visible on your webserver. You can read all about
cfgmaker in cfgmaker. One area you might want to look at is the possibility of
to prevent interface renumbering troubles from
If you want to start rolling your own mrtg configuration files, make sure you
read mrtg-reference to learn all about the possible configuration options.
Once you have created a configuration file, try the following:
This will query your router and also create your first mrtg trafic graphs and
webpages. When you run mrtg for the first time there will be a lot of
complaints about missing log files. Don't worry, this is normal for the first
2 times you start mrtg. If it keeps complaining after this time you might want
to look into the problem.
Starting mrtg by hand is not ideal in the long run. So when you are satisfied
with the results you can automate the process of running mrtg in regular
intervals (this means every 5 minutes by default).
You can either add mrtg to your crontab with a line like this:
0,5,10,15,20,25,30,35,40,45,50,55 * * * * \
<mrtg-bin>/mrtg <path to mrtg-cfg>/mrtg.cfg \
or if you live in Linux Land the line may look like this if you are using
*/5 * * * * <mrtg-bin>/mrtg <path to mrtg-cfg>/mrtg.cfg \
or like this if you use /etc/crontab
*/5 * * * * mrtg-user <mrtg-bin>/mrtg <path to mrtg-cfg>/mrtg.cfg \
You can also run mrtg as a daemon process by adding the line
to your mrtg configuration file and then creating a startup script in your
system startup sequence. Unfortunately, adding startup scripts differs widely
amongst different unix systems. The modern ones normally have a directory
where you put scripts
which starts the process you want to run when the system boots. Further you
must create a symbolic link in /etc/rc3.d
(this is just a sample name ... it is just important
that it starts with S followed by a two digit number). If you are not sure
about this, make sure you consult the documentation of your system to make
sure you get this right.
script to put into init.d
might look like this:
cd /usr/local/mrtg-2.17.4/bin && ./mrtg --user=mrtg-user \
/home/httpd/mrtg/mrtg.cfg --logging /var/log/mrtg.log
Note that this will only work with RunAsDaemon: Yes
in your mrtg.cfg
Tobias Oetiker <firstname.lastname@example.org>