Prerequisites
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
Enable the Universe Repositories
First, make sure you have the universe repositories enabled on your system. Your /etc/apt/sources.list should resemble the following (you may have to uncomment or add the universe lines):
File:/etc/apt/sources.list
## main & restricted repositories
deb http://us.archive.ubuntu.com/ubuntu/ lucid main restricted
deb-src http://us.archive.ubuntu.com/ubuntu/ lucid main restricted
deb http://security.ubuntu.com/ubuntu lucid-security main restricted
deb-src http://security.ubuntu.com/ubuntu lucid-security main restricted
## universe repositories - uncomment to enable
deb http://us.archive.ubuntu.com/ubuntu/ lucid universe
deb-src http://us.archive.ubuntu.com/ubuntu/ lucid universe
deb http://us.archive.ubuntu.com/ubuntu/ lucid-updates universe
deb-src http://us.archive.ubuntu.com/ubuntu/ lucid-updates universe
deb http://security.ubuntu.com/ubuntu lucid-security universe
deb-src http://security.ubuntu.com/ubuntu lucid-security universe
If you had to enable new repositories, issue the following command to update your package lists:
apt-get update apt-get upgrade
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 on 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 running PHP as a FastCGI process.
Configuring SNMPD
SNMPD binds to localhost by default. If you only plan on using Cacti to monitor your Linode, you do not need to modify /etc/default/snmpd. However, if you'd like to use Cacti to monitor more than one host, you'll need to edit the /etc/default/snmpd file. Open the file and find the line that starts with SNMPDOPTS= and remove 127.0.0.1 at the end. This line should now look like this:
File:/etc/default/snmpd
SNMPDOPTS='-Lsd -Lf /dev/null -u snmp -g snmp -I -smux -p /var/run/snmpd.pid'
At this point SNMPD is configured to listen on all interfaces. 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 cactiYou 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 Debian-based distributions, but with modification, they will work on any flavor of Linux. You will need to follow these instructions for each client machine you'd like to monitor with 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 snmpdNext 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 mycommunity" > /etc/snmp/snmpd.confNote 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 -g snmp -I -smux -p /var/run/snmpd.pid'
/etc/init.d/snmpd restartAt 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 the Spine installation by running the following commandapt-get install cacti-spineAfter 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.
