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Introduction
This page gives some basic information about installation and configuration of MRTG under Linux. The reference page is
MRTG.
Necessary tools and libraries
You need:
- a C compiler (gcc or ecgs...)
- a not too old perl version (at least 5.004_4)
- snmp running as a daemon (Simple Network Management Protocol)
All these tools are usually available in most distributions. For snmp, I use ucd-snmp whichi is available in
some distributions as a package. You can have a look at:
http://net-snmp.sourceforge.net/.
Jean-Louis Noel proposed a script netstat
for measuring interfaces input/output which does not require snmp. I think this is safer and easier to use this script if you do not
need advanced function required by snmp. See further how to use it.
You also need gd from Thomas Boutell (www.boutell.com).
I have here
gd 1.8.4 .
To install gd, you need libpng, zlib and jpeg 6b at least. These libraries are generally available in most distributions.
You can have a look at:
Sinon, voir
ftp://ftp.freesoftware.com/pub/infozip/zlib/ for zlib,
ftp://ftp.freesoftware.com/pub/png/src/ for libpng, and
http://www.ijg.org/ for jpeg.
Finally you need MRTG sources. I have here MRTG 2.9.17.
Be careful!
Check that you have an empty (if you trust you LAN end snmp port is closed from outside)
config file snmp.conf in /etc or /usr/share/snmp (or elsewhere...), or containing:
com2sec readonly localhost public
Some distribution provides a default config file which does not allow MRTG to work as:
com2sec paranoid default public
gd installation
So, you already installed zlib, libpng and jpeg (sorry, I do not give explanations for these libraries, their installation is standart).
Uncompress (tar -zxf gd-1.8.4.tar.gz) gd source in (for example) /usr/local/src/. Go to gd directory and
edit the Makefile. This is the part to edit:
COMPILER=gcc
AR=ar
CFLAGS=-O -DHAVE_LIBPNG -DHAVE_LIBJPEG -DHAVE_LIBXPM -DHAVE_LIBTTF
LIBS=-lgd -lpng -lz -ljpeg -lm -lttf
INCLUDEDIRS=-I. -I/usr/include/freetype -I/usr/include/X11 \
-I/usr/X11R6/include/X11 -I/usr/local/include
LIBDIRS=-L. -L/usr/local/lib -L/usr/lib/X11 -L/usr/X11R6/lib
INSTALL_LIB=/usr/local/lib
INSTALL_INCLUDE=/usr/local/include
INSTALL_BIN=/usr/local/bin
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Modify the lines COMPILER, CFLAGS, LIBS and INCLUDEDIR according to your configuration (read the comments in the Makefile
and the readme.txt of gd, for freetype for instance).
Setup INSTALL_LIB, INSTALL_INCLUDE et INSTALL_BIN if you want an install in other directories.
Run make and if there are no errors, run make install.
MRTG Installation
Uncompress (tar -zxf mrtg-2.9.17.tar.gz). From the MRTG directory run ./configure. If all is OK, you get
a Makefile...after ordering MRTG CD (:-D). Now run make. Si le./configure a produit des
messages d'erreur, lisez les, c'est qu'il
vous manque des librairies ou outils de développement.
make install will install mrtg in /usr/local/mrtg-2
All the necessary pogrammes are in /usr/local/mrtg-2/bin.
MRTG configuration
In the directory /usr/local/mrtg-2/bin, there is a tool cfgmaker which builds a "beginning" of the
configuration file. Go to a temp directory and run:
/usr/local/mrtg-2/bin/cfgmaker public@machine_name >test
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where machine_name is the hostname of your machine. You get the list of your interfaces in the file test and
the "beginning of a configuration file".
You can see here the file test on my machine.
As you can see, there are 5 interfaces: loopback, dummy0, 2 ethernet and PPP0. For each interface, a name is proposed. In your final
configuration file, you can (or should) change these names, you can also decide to not mention all these interfaces.
cfgmaker can also configure interfaces by their ip (option -ifref=ip). Run ./cfgmaker --help from the mrtg bin directory for a list
of all options and have a look at all available documentation on
MRTG website.
Chose a working directory (in your website root directory if you want ro give access to yout mrtg pages). Make a mrtg.cfg
in this directory. Start with a line like WorkDir: /web/mrtg (or use a different directory fo logs, images and html with
Logdir, Imagedir and Htmldir options, have a look at my config file) . Then copy the "pieces" of
test which correspond to the interfaces you want to measure. Though in my file foo
ppp0 was marked "unrealistic", it is the one I use!!
For each interface, you have to chose a name for each "target" order. Mrtg will generate a "name.html" file. Do not forget to copy the *.png
Mrtg images from the Mrtg directory to to you Workdir or you Imagedir.
To know all the available option, have a look at the doc directrory in Mrtg install directory.
Run "mrtg mrtg.cfg" and look what happens... if all is OK, Mrtg created html files in Workdir or Htmldir. The two first run of Mrtg
generate warning messages, they disappear at the third run. Now, you can run mrtg from a cron job in /etc/crontab.
The default time intervall is 5 minutes. If you want to change this, you have to use Intervall keyword and change you cron job accordingly.
indexmaker (available in /usr/local/mrtg-2/bin) allows to make a page with access to your
Mrtg pages.
You should read the doc about [_] which defines default options and [^] which defines "prefix" for targets
and [$] whiche defines "suffix" for targets.
An example is better than long explanations, have a look at my config file on linux-sottises.
MRTG for pings and other tricks
Mrtg permits to make charts for "anything"! using some scripts. Do not forget to make
those script "x" by chmod u+x.
You can see all the results of these script on the page
stats_mrtg.
Remark: mrtg stats has been stopped on April 17 2002 as linux-sottises uses MRTNK which
is based on RRDTOOL, you can have a look at the graphics generated by MRTNK.
The current stable version of MRTNK is available on the software page.
The development version (which is always the one used at linux-sottises)
is available here.
For the moment, only the french documentation is avaliable for the development version in the doc directory.
PING.
It is target [ping_nerim] of my config file.
You can download ping-nerim script
which gives min et max over 3 pings.
APACHE
Mrtg can also count the hits number on you Apache server
(server-status and ExtendStatus must be enabled in your apache config file)
It is target [apache] in my config file.
The perl script is webstat.pl. This script can also measure
apache traffic, look at the section [apache_byte of my
config file.
To measure separatly hits and and traffic/documents of virtual hosts, I use mod_watch
www.snert.com/Software/mod_watch/
You must hace compiled apache yourself.
There are 2 options of compilation of mod_watch, as a dynamic module if apache has been
compiled with dynamic modules support, or statically.
I only use mod_watch as a dynamic module and only have explanations for this compilation.
After downloading and compiling it, edit the Makefile. Modify to path to you apache sources
in APACHEDIR, the path to the scripts used by mod_watch in SCRIPTDIR, the path of virtual
servers logs in SPOOLDIR.
If apache apxs is not in your path, you have to modify APXS a little further in the Makefile.
For example, for me it is:
APXS=/usr/local/apache/bin/apxs
Then run make install-dynamic
Check that mod_watch has been added up in your apache config file and that the module is
effectly in libexec directory of you apache install directory.
Then add in you apache config file:
<IfModule mod_watch.c>
<Location /watch-info>
SetHandler watch-info
</Location>
</IfModule>
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Stop and start apache.
goto /watch-info on you server from your browser to check that mod_watch
is active. Go to
www.snert.com/Software/mod_watch/
for more details.
Have a look at my MRTG config file
to have a look at the 4 mod_watch sections and
stats_mrtg to see all the results.
UPTIME
For uptime I use perl script uptime.pl
and the corresponding target is [uptime] in my config file.
PROCESS
To count the number of processes, I use the perl script
stat.pl, target [procs] in my config file.
MEMORY
For memory, I use mem, target [mem] in my config file.
DNS
For DNS queries (bind V8), it is the same script as process number stat.pl, target [dns] in my config file.
CPU
For CPU, it is a bit more complex. The script is cpustat, target [cpu] in my config file. But, you need to install
sysstat-4.0.3. Have a look at
http://perso.wanadoo.fr/sebastien.godard/ systat author page.
systat must be installed and regularly launched by cron.
NETWORK INTERFACES WITHOUT SNMP
To measure interfaces without snmp, you can use netstat.
Check cut, grep and uptime location. Usage is:
Target[target_ppp0]: `path_to_netstat target_ppp0 ppp0`
first parameter is the name of the target, the second one is the interface name.
David Du Serre-Telmon proposed another script
netstat-ip which permits to call an interface
by its IP.
Usage is straightforward: netstat target_name interface or netstat target_name ip ip_value.
OPEN FILES
A script proposed by 0_be_one counts the
number of open files (you need lsof).
The perl script is files.pl. Look at the section [files]
of my config file.
DISK SPACE
A script from AIREY Romuald give disk space.
It is based on df command, example:
Filesystem 1k-blocks Used Available Use% Mounted on
/dev/sda3 8625436 3168832 5018432 39% /
/dev/sda1 23300 5193 16904 24% /boot
/dev/hda1 59084932 44493936 14590996 76% /mnt/idea
/dev/hdb1 38448276 9756360 26738816 27% /mnt/ideb
192.168.0.6:/ 3984704 934288 2848000 25% /pluto
192.168.0.7:/ 1921188 507476 1316120 28% /vador
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option -m for Mo is used (for better readness and respect the max integer of MRTG, it is also
advised to eliminate nfs file systems by -x nfs (if nfs servers are down, you will get problems
with the script!).
df -m -x nfs :
Filesystem 1M-blocks Used Available Use% Mounted on
/dev/sda3 8423 3089 4907 39% /
/dev/sda1 23 6 16 24% /boot
/dev/hda1 57700 43452 14249 76% /mnt/idea
/dev/hdb1 37547 9528 26112 27% /mnt/ideb
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The script checkdisk returns free and used disk space.
Check df, cut and grep location.
checkdisk is used followod by the partition name, have a look at sections hda1, hdb1 and sda3
of my config file.
Have a look at the use of kMG which is required to avoid kMo in place of Go!!
DATA EXCHANGE AMOUNT ON AN INTERFACE
volume gives the amount of data exchanged
on an interface.
As this tiny script is based on
ifconfig, an interface down-up reset the statistics to 0,..., what I do not feel disturbing.
The data appearing through ifconfig is also reset
when some maximum is reached (I did no try to evaluate this maximum).
it is very easy to use: volume interface_name (have a look at volume_ppp0 of my
config file and the results on
stats_mrtg.
ACTIVE TCP CONNECTIONS WITH NETFILTER
This was contributed by David Du Serre-Telmon. The script is
tcpcount.
use is:
tcpcount => total tcp connections through the gateway
tcpcount 21 => FTP connections
tcpcount 80 dst www.linux-sottises.net => web connections to www.linux-sottises.net
tcpcount 1214 src 192.168.0.2 => Kazaa connections fo user 192.168.0.2
If you have difficulties or questions, all email are welcome to
tnka at linux-sottises.net.
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