unix-guide - Instructions for running MRTG 2.9.5 on a Unix
Box
SYNOPSIS
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 so.
PREPARATION
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.
GCC The GNU C compiler comes pre installed on most of the
free Unicies out there. For commercial Derivats 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 avail
able for most of the operating systems.
http://gcc.gnu.org/
Perl
Larg 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 ver
sion 5.005 is required for mrtg to work well. You can
get the latest perl from
http://www.perl.com/
MRTG generates traffic graphs in the PNG format. To be
able todo this it needs several 3rd party libraries. When
compiling these libraries I urge you to make sure you com
pile them as static, non shared 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 though 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.
gd 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.
http://www.boutell.com/gd/
libpng
Is required by gd in order to produce PNG graphics
files. Get it from:
http://www.libpng.org/pub/png/
zlib
Finally is needed by libpng to compress the graphics
files you create. Get a copy from
http://www.info-zip.org/pub/infozip/zlib/
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:
http://ee-staff.ethz.ch/~oetiker/webtools/mrtg/pub
LIBRARY COMPILATION
In this section I will give you 1:1 instructions on how to
compile the various libraries required for the compilation
of mrtg. Note that these libaries may already be installed
if you have a *BSD or Linux system. The wget programm used
below is a simple web downloader you can also enter the
address into your netscape if you don't have wget avail
able.
First lets 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
cd /usr/local/src
If you do not have zlib installed:
wget http://ftp.info-zip.org/pub/infozip/zlib/zlib.tar.gz
gunzip -c zlib.tar.gz | tar xf -
mv zlib-?.?.?/ zlib
cd zlib
./configure
make
cd ..
If you don't have libpng installed
gunzip -c libpng-1.0.8.tar.gz |tar xf -
mv libpng-1.0.8 libpng
cd libpng
make -f scripts/makefile.std CC=gcc ZLIBLIB=../zlib ZLIBINC=../zlib
rm *.so.* *.so
cd ..
And now you can compile gd
wget http://www.boutell.com/gd/http/gd-1.8.3.tar.gz
gunzip -c gd-1.8.3.tar.gz |tar xf -
mv gd-1.8.3 gd
cd gd
The \ characters at the end of the line mean that all the
following material should actually be written on a single
line.
make INCLUDEDIRS="-I. -I../zlib -I../libpng" \
LIBDIRS="-L../zlib -L. -L../libpng" \
LIBS="-lgd -lpng -lz -lm"
cd ..
MRTG COMPILATION
Ok now everything is ready for the mrtg compilation.
cd /usr/local
gunzip -c mrtg-2.9.6.tar.gz | tar xvf -
cd mrtg-2.9.6
If you all the libraries have been preinstalled on your
system you can configure mrtg by doing a simple:
./configure
Otherwise you may have to give some hints on where to find
the various libraries required to compile mrtg:
./configure --with-gd=/usr/local/src/gd \
--with-z=/usr/local/src/zlib \
--with-png=/usr/local/src/libpng
If you have RRDtool available you might want to tell mrtg
about it so that you can opt to use rrdtool with mrtg.
Check the mrtg-rrd manpage.
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 todo about it. If every
thing is OK, you will end up with a custom Makefile for
your system. Now type:
This builds the rateup binary and edits all the perl path
names in the scripts. All the software required by MRTG is
now in the run subdirectory.
You can now safely delete the libraries we compiled above.
But then again you might want to keep them around so that
you have them available when compiling the next version of
mrtg.
CONFIGURATION
The next step is now to configure mrtg for monitoring an
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 con
figuration file all by yourself. Together with mrtg you
also got a copy of cfgmaker. This is a script you can
point at a router of your choice; and it will create a
mrtg configuration file for you. You can find the script
in the bin subdirectory.
cfgmaker --global 'WorkDir: /home/httpd/mrtg' \
--global 'Options[_]: bits,growright' \
--output /home/httpd/mrtg/mrtg.cfg \
community@router.abc.xyz
This example above will create an mrtg config file in
/home/httpd/mrtg assuming this is a directory visible on
your webserver. You can read all about cfgmaker in the
cfgmaker manpage. One area you might want to look at is
the possibility of using --ifref=ip to prevent interface
renumbering troubles from catching you.
If you want to start rolling your own mrtg configuration
files, make sure you read the reference manpage to learn
all about the possible configuration options.
RUNNING MRTG
Once you have created a configuration file, try the fol
lowing:
/usr/local/mrtg-2.9.6/bin/mrtg /home/httpd/mrtg/mrtg.cfg
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 sattisfied with the results you must automate
the process of running mrtg in regular intervals (this
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 `crontab -e'
*/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
RunAsDaemon: Yes
to your mrtg configuration file and then creating a
startup script in your system startup sequence. Unfortu
nately, adding startup scripts differs widely amongst dif
ferent unix systems. The modern ones normally have a
directory called /etc/inid.d or /etc/rc.d/init.d 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 or /etc/rc.d/rc?.d called S65mrtg (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.
A minimal script to put into init.d might look like this:
#! /bin/sh
cd /usr/local/mrtg-2.9.6/bin && ./mrtg --user=mrtg-user /home/httpd/mrtg/mrtg.cfg
Note that this will only work with RunAsDaemon: Yes in
your mrtg.cfg file.
AUTHOR
Tobias Oetiker <oetiker@ee.ethz.ch>
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