How to Install and configure Zabbix agent 4.0 on Ubuntu 18.04 and CentOS 7

Welcome to our guide on How to Install and configure Zabbix agent 4.0 on Ubuntu 18.04 and CentOS 7. In our previous guide, we covered the installation of Zabbix Server, both for Ubuntu and CentOS 7:

How to Install Zabbix Server 4.0 on Ubuntu 18.04 & Ubuntu 16.04 LTS

How to Install Zabbix Server 4.0 on CentOS 7

This is a continuation guide on Zabbix monitoring of your entire Infrastructure – Linux systems, Windows servers, network routers, network switches e.t.c. So let’s get started with how to Install and configure Zabbix agent 4.0 on CentOS 7 and Ubuntu 18.04.

What is Zabbix Agent?

Zabbix agent is a program developed in C. It runs on various supported platforms, including Linux, UNIX, and Windows. The work of the Zabbix agent is to collect data such as CPU, memory, disk and network interface usage from a device. It has a small resource footprint considering that monitoring configurations are centralized on the Zabbix server.

How Zabbix agent works

Zabbix agent can do both passive (polling) and active checks (trapping). The checks can be performed at an interval or based on specific times schedule. Here is the difference between passive and active checks:

Passive checks (polling):

• Zabbix server (or proxy) requests a value from Zabbix agent
• Agent processes the request and returns the value to the Zabbix server (or proxy)

Active checks (trapping):

• Zabbix agent requests from Zabbix server (or proxy) a list of active checks
• The agent sends the results in periodically

The image below from Zabbix may help visualize passive and active checks in action:

How to Install Zabbix agent on CentOS 7

Below steps are used to install Zabbix agent on CentOS 7

 Add Zabbix repositories

Add Zabbix 4.0 repositories using the commands below:

rpm -ivh https://repo.zabbix.com/zabbix/4.0/rhel/7/x86_64/zabbix-release-4.0-1.el7.noarch.rpm

Once the repo has been added, install Zabbix agent by executing the following command on your terminal.

sudo yum install zabbix-agent zabbix-sender

How to Install Zabbix agent on Ubuntu 18.04

Add Zabbix 4.0 repository on Ubuntu 18.04 (Bionic Beaver) LTS:

wget https://repo.zabbix.com/zabbix/4.0/ubuntu/pool/main/z/zabbix-release/zabbix-release_4.0-2+bionic_all.deb
sudo dpkg -i zabbix-release_4.0*
sudo apt update

Add Zabbix 4.0 repository on Ubuntu 16.04 (Xenial Xerus) LTS:

wget https://repo.zabbix.com/zabbix/4.0/ubuntu/pool/main/z/zabbix-release/zabbix-release_4.0-2+xenial_all.deb
sudo dpkg -i zabbix-release_4.0*

Then install Zabbix agent

sudo apt install zabbix-agent zabbix-sender

Step 2: Configuring Zabbix Agent

Zabbix agent configuration is /etc/zabbix/zabbix_agentd.conf. Edit

# cat /etc/zabbix/zabbix_agentd.conf
# On line 97 - Specify Zabbix server IP Address
Server=192.168.10.2
# On line 138 - Specify Zabbix server ( For active checks)
ServerActive=192.168.10.2
# On line 150 - Set server hostname reported by Zabbix agent
Hostname=server1.example.com

Start zabbix-agent after making the change, also enable the service to start on boot:

sudo systemctl start zabbix-agent
sudo systemctl enable zabbix-agent

You can check service status using the command:

$ sudo systemctl status zabbix-agent
● zabbix-agent.service - Zabbix Agent
Loaded: loaded (/usr/lib/systemd/system/zabbix-agent.service; enabled; vendor preset: disabled)
Active: active (running) since Tue 2018-10-16 22:30:00 UTC; 50s ago
Main PID: 28026 (zabbix_agentd)
CGroup: /system.slice/zabbix-agent.service
├─28026 /usr/sbin/zabbix_agentd -c /etc/zabbix/zabbix_agentd.conf
├─28027 /usr/sbin/zabbix_agentd: collector [idle 1 sec]
├─28028 /usr/sbin/zabbix_agentd: listener #1 [waiting for connection]
├─28029 /usr/sbin/zabbix_agentd: listener #2 [waiting for connection]
├─28030 /usr/sbin/zabbix_agentd: listener #3 [waiting for connection]
└─28031 /usr/sbin/zabbix_agentd: active checks #1 [idle 1 sec]

If you have firewalld enabled, allow port 10050/tcp on the firewall. This is used by Zabbix agent daemon.

For CentOS 7:

sudo firewall-cmd --permanent --add-port=10050/tcp
sudo firewall-cmd --reload

For Ubuntu (UFW)

sudo ufw allow 10050/tcp

You can check service port if listening using ss or netstat commands:

# ss -tunelp | grep 10050
tcp    LISTEN     0      128       *:10050                 *:*                   users:(("zabbix_agentd",pid=28031,fd=6),("zabbix_agentd",pid=28030,fd=6),("zabbix_agentd",pid=28029,fd=6),("zabbix_agentd",pid=28028,fd=6),("zabbix_agentd",pid=28027,fd=6),("zabbix_agentd",pid=28026,fd=6)) uid:385 ino:15465825 sk:ffffa119c2e264c0 <->
tcp    LISTEN     0      128      :::10050                :::*                   users:(("zabbix_agentd",pid=28031,fd=7),("zabbix_agentd",pid=28030,fd=7),("zabbix_agentd",pid=28029,fd=7),("zabbix_agentd",pid=28028,fd=7),("zabbix_agentd",pid=28027,fd=7),("zabbix_agentd",pid=28026,fd=7)) uid:385 ino:15465826 sk:ffffa11973db8880 v6only:1 <-

Step 3: Add host to Zabbix Server

Login to admin Zabbix server interface, and go to Configuration > Hosts > Create host. Provide the following information:

• Hostname of the server to be monitored
• The visible name of the server to be monitored.
• Select the group or add a new group for “Groups” field.
• IP address
• Zabbix agent service port -default is 10050

Then go to the Templates tab.

1. Click the select button under Link new templates section

Select the templates you want to use:

2. Once you have selected the templates, click on the Add link to link templates to your target systemAfter the templates are linked, they’ll appear on the  Linked templates section

Update the setting using the Update button.

After a few minutes, monitoring data will be collected and you can visualize them using Zabbix graphs. Default host graphs can be accessed on

Monitoring > Graphs > <Host|Graph>

Below are the Ram and CPU utilization graphs for the host we added earlier.