instalasi cacti spine pada debian squeeze

republished. :)

================================================================

Monitoring Resource Utilization with Cacti on Debian 6 (Squeeze)
================================================================
:Author: Stan Schwertly 
:Description: Monitor resource usage through the powerful server monitoring tool Cacti on Debian 6 (Squeeze).
:Location: http://library.linode.com/server-monitoring/cacti/debian-6-squeeze
:Keywords: monitoring,cacti,snmp,debian,debian 6,squeeze,debian squeeze
:License: `CC BY-ND 3.0 `_
:Published: Wednesday, November 9th, 2011
:Modified: Wednesday, November 9th, 2011 by Amanda Folson




The Linode Manager provides some basic monitoring of system resource
utilization, which includes information regarding Network, CPU, and
Input/Output usage over the last 24 hours and 30 days. While this
basic information is helpful for monitoring your system, there are
cases where more fine-grained information is useful. The simple
monitoring tool `Munin `_ is 
capable of monitoring needs of a small group of machines. In
some cases, Munin may not be flexible enough for some advanced
monitoring needs.

For these kinds of deployments we encourage you to consider a tool
like Cacti, which is a flexible front end for the RRDtool
application. Cacti simply provides a framework and a mechanism to poll
a number of sources for data regarding your systems, which can then be
graphed and presented in a clear web based interface. Whereas packages
like Munin provide monitoring for a specific set of metrics on systems
which support the Munin plug in, Cacti provides increased freedom to
monitor larger systems and more complex deployment by way of its
plug in framework and web-based interface. 

Before installing Cacti we assume that you have followed our `getting
started guide `_. If you're new to Linux server
administration you may be interested in our `using Linux `_
document series including the `beginner's guide `_
and `administration basics guide `_. 

.. contents:: Contents

Installing Prerequisites
------------------------

Make sure your package repositories and installed programs are up to
date by issuing the following commands::

    apt-get update
 apt-get upgrade --show-upgraded

Set the Timezone
~~~~~~~~~~~~~~~~

Begin by setting the timezone of your server if it isn't already set. 
Set your server to your timezone or to that of the bulk of your users.  
If you're unsure which timezone would be best, consider using 
universal coordinated time (or UTC, ie. Greenwich Mean Time). Keep in mind 
that Cacti uses the timezone set on the monitoring machine when generating 
its graphs. Run the following command to set the timezone::

 dpkg-reconfigure tzdata

Installing Dependencies
~~~~~~~~~~~~~~~~~~~~~~~

Before installing Cacti we must install a few basic dependencies that are 
critical to the installation of Cacti. Cacti uses the Simple Network 
Management Protocol (SNMP) to poll the devices it tracks. We'll need to 
install the ``snmpd`` and ``snmp`` packages to allow Cacti to use SNMP. 
Cacti's web interface requires a database, web server, and PHP to be 
installed. Issue the following command to install these prerequisites::

 apt-get install snmpd snmp mysql-server apache2 libapache2-mod-php5 \
 php5-mysql php5-cli php5-snmp

You will need to create a password for the ``root`` user of your MySQL
database during the installation. After the installation completes, be 
sure to run ``mysql_secure_installation`` to disable some of MySQL's less
secure components. Also consider reading our `MySQL installation guide `_
for configuration recommendations. 

The above command will additionally install the Apache web server. Consider 
our documentation of `installing the Apache HTTP Server `_ 
for more information regarding this server. Additionally Cacti can function
with alternate web server configurations, including `Apache with PHP
running as a CGI process `_ 
and with `Nginx with PHP running as a FastCGI process `_.

Configuring SNMPD
~~~~~~~~~~~~~~~~~

SNMPD binds to all addresses by default. If you only plan on using Cacti to monitor
your Linode, you have the option to configure SNMPD to only bind to ``localhost`` by editing the
``/etc/default/smnpd`` file. Open the file and find the line that starts with
``SNMPDOPTS=`` and add ``127.0.0.1`` at the end.  This line will now look like
this:

.. file:: /etc/default/snmpd

    SNMPDOPTS='-Lsd -Lf /dev/null -u snmp -g snmp -I -smux -p /var/run/snmpd.pid 127.0.0.1'

You can also specify which external IP address SNMPD binds to by adding it to the end
as well. Now we'll open ``/etc/snmp/snmpd.conf`` to establish which host is trusted to receive
data. 

We'll create an SNMP "community" to help identify our group of devices 
for Cacti. In this instance, our hostname is "bucknell.org",
so we've named the community "Bucknell". The community name choice is up 
to the user. Locate the section of ``snmpd.conf`` that begins with ``com2sec``
and make sure the ``readonly`` line is the only uncommented line. This section 
of the file should now look like this:

.. file:: /etc/snmp/snmpd.conf

 #com2sec paranoid  default         public
 com2sec readonly  localhost        Bucknell
 #com2sec readwrite default         private

If you want a remote machine to connect to Cacti, replace "localhost" with
the IP address of the remote machine. 

You need to restart snmpd any time ``/etc/snmp/snmpd.conf`` is modified. 
Run the following command after closing the file: ::
 
 /etc/init.d/snmpd restart

Installing Cacti
----------------

To install the Cacti package from the distribution software
repositories, issue the following command::

 apt-get install cacti

You will be presented with several prompts during this installation. On
the "libphp-adodb" prompt you can safely select "Ok". During the "Configuring
Cacti" prompt, make sure to select "Apache2." You will be presented with
an additional "Configuring cacti" prompt that will ask if you'd like 
to configure your database with dbconfig-common. Select "Yes" and continue.
On the MySQL prompt, enter the root password you created earlier. On the 
next screen, either create your own password for cacti's database access, or
leave it blank for it to automatically generate one for you.

From here we'll continue configuring Cacti through the browser. Visit
the domain you have pointed at your Linode, or your Linode's IP address, and
add ``/cacti``. Follow the instructions shown on each page. Make sure to
select ``RRDTool 1.2.x`` in the "RRDTool Utility Version" drop down. You 
should be  able to continue through these pages into the login page 
without alteration.

At the login screen, enter ``admin/admin`` for the username/password combination.
You'll be prompted to change your password on the next screen. At this point,
Cacti is installed and ready to be configured.

Configuring Cacti
-----------------

At this point Cacti will contain an entry for ``localhost``, which we'll
need to modify. Click the "Console" tab in the top left corner, and select
"Create Devices for network". Click the "Localhost" entry to begin making
the needed changes. Select the Host Template drop down and pick the "ucd/net SNMP Host".
Scroll down to SNMP Options and click the drop down box for SNMP Version, 
picking "Version 1". Enter "Bucknell" (or the community name you created above) 
in the box for the "SNMP Community" field. The "Associated Graph Templates" 
section allows you to add additional graphs. Hit "Save" to keep the changes. 

Click "Settings" under "Configuration" and set your "SNMP Version" to 
"Version 1" in the drop down box. Type the name of your community for 
the "SNMP Community" (in this example, "Bucknell") and save.

Configuring Client Machines
---------------------------

This section is optional and for those looking to use Cacti to monitor 
additional devices. These steps are written for other Debian-based distributions, 
but with modification, will work on any flavor of Linux. You will need 
to follow these instructions for each client machine you'd like to monitor 
in Cacti. Client machines need an SNMP daemon in order to serve Cacti 
information. First, install ``snmp`` and ``snmpd`` on the client::

 apt-get install snmp snmpd

Next we'll need to modify the ``/etc/snmp/snmpd.conf`` file with the name 
of our community. Run the following commands to backup your existing ``snmpd.conf`` 
file and replace the contents with the name of your community::

 mv /etc/snmp/snmpd.conf /etc/snmp/old.snmpd.conf
 echo "rocommunity community_name" > /etc/snmp/snmpd.conf

Note that the format is "rocommunity community_name", where ``community_name`` 
is the name of the community you originally used with Cacti. Next, we'll 
open the ``/etc/default/snmpd`` file and remove the binding on ``localhost``. 
Like the "Configuring SNMP" section above, you'll want to find the line 
that begins with ``SNMPDOPTS`` and remove the reference to ``127.0.0.1`` at 
the end. This line should now resemble the one below:

.. file:: /etc/default/snmpd

 SNMPDOPTS='-Lsd -Lf /dev/null -u snmp -I -smux -p /var/run/snmpd.pid'

Finally, restart the SNMP daemon to push the changes you've made to these 
files::

 /etc/init.d/snmpd restart

At this point your machine is ready for polling. Go into the Cacti interface 
to add the new "Device". Under the "Console" tab, select "New Graphs" and then 
"Create New Host". Enter the pertinent information in the fields required. 
Make sure to select "Ping" for "Downed Device Detection". Additionally, ensure 
that you've typed the right community name in the "SNMP Community" field. 
Click the "create" button to save your configuration. On the "save successful" 
screen, select your newly created device and from the drop down next to 
"Choose an Action" select "Place on a Tree" and then click "go". Hit "yes" 
on the next screen. On the "New Graphs" screen, you'll be able to create 
several different types of graphs of your choice. Follow the on-screen 
instructions to add these graphs to your tree.

Using the Spine Polling Daemon
------------------------------

By default, Cacti uses a PHP script to poll the devices it tracks. "Spine" 
is a faster replacement for the default polling script written in C++. 
Installing Spine is relatively easy and a good idea if you plan on keeping
track of many hosts. Begin installing Spine by running the following command ::

 apt-get install cacti-spine

After the installation completes, go back to the Cacti administrative 
panel and click "Settings" under "Configuration". Click the "Paths" tab
and check to see that Cacti found your spine binary correctly. Click the
"Poller" tab and choose "Spine" from the drop-down for "Poller Type". Click
"Save" to keep these changes. You are now successfully using Spine.


More Information
----------------

.. moreinfo::

 - `Cacti Website `_
 - `Cacti Users Plugin Community `_
 - `Linux Security Basics `_
 - `Control Network Traffic with iptables `_

.. container:: license

 .. image:: /media/images/cc.png
  :alt: Creative Commons License

 This guide is licensed under a `Creative Commons Attribution-NoDerivs 3.0
 United States License `_.

 Last edited by Amanda Folson on Wednesday, November 9th, 2011 (r2654).

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