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How to Install OpenNMS on Fedora

OpenNMS, also called “Open Network Management System,” is a free and cross-platform network management platform for Linux and Windows-based operating systems. It is a Java-based tool designed to monitor critical services on remote machines via SNMP and JMX. OpenNMS comes with a web-based console that helps you to monitor and administer networks and applications.

In this tutorial, we will show you how to install OpenNMS on Fedora.


  • A server running Fedora 34 on the Atlantic.Net Cloud Platform
  • A root password is configured on your server

Step 1 – Create Atlantic.Net Cloud Server

First, log in to your Atlantic.Net Cloud Server. Create a new server, choosing Fedora 34 as the operating system with at least 2GB RAM. Connect to your Cloud Server via SSH and log in using the credentials highlighted at the top of the page.

Once you are logged in to your server, run the following command to update your base system with the latest available packages.

dnf update -y

Step 2 – Install Java JDK

OpenNMS is based on Java, so you will need to install the Java JDK on your server. You can install it with the following command.

dnf install java-11-openjdk

After the successful installation, you can verify the Java installation with the following command.

java --version


openjdk 11.0.15 2022-04-19
OpenJDK Runtime Environment 18.9 (build 11.0.15+10)
OpenJDK 64-Bit Server VM 18.9 (build 11.0.15+10, mixed mode, sharing)

Step 3 – Install and Configure PostgreSQL Database

OpenNMS uses PostgreSQL as a database backend, so you will need to install and configure PostgreSQL to your server.

First, disable the default PostgreSQL repo and enable the PostgreSQL 14 repo with the following command.

dnf module reset postgresql -y
dnf module enable postgresql:14

Next, install the PostgreSQL server with the following command.

dnf install postgresql-server postgresql

Next, initialize the PostgreSQL database using the following command.

postgresql-setup --initdb

Next, start and enable the PostgreSQL service with the following command.

systemctl enable --now postgresql

Next, log in to PostgreSQL:

su - postgres

Create a database and user for OpenNMS with the following command.

create user opennms;
create database opennms owner opennms;
grant all privileges on database opennms to opennms;

Next, set OpenNMS and Postgres password with the following command.

ALTER USER opennms WITH ENCRYPTED password 'secure_password';
ALTER USER postgres WITH PASSWORD 'secure_password';

Finally, exit from the PostgreSQL shell with the following command.


Next, edit the PostgreSQL configuration file.

nano /var/lib/pgsql/data/pg_hba.conf

Find the following lines:

host    all             all               ident
host    all             all             ::1/128                 ident

And replace them with the following lines:

host    all             all               md5
host    all             all             ::1/128                 md5

Save and close the file, then reload PostgreSQL to implement the changes.

systemctl reload postgresql

Step 4 – Install and Configure OpenNMS

First, add the OpenNMS repo and import the GPG key using the following command.

dnf -y install
rpm --import

Next, install the OpenNMS package with the following command.

dnf install opennms -y

Next, edit the OpenNMS database configuration file.

nano /opt/opennms/etc/opennms-datasources.xml

Define your database details as shown below.

<jdbc-data-source name="opennms"
                    password="secure_password" />

<jdbc-data-source name="opennms-admin"
                    password="secure_password" />

Save and close the file, then run the following command to detect the Java environment.

/opt/opennms/bin/runjava -s


runjava: Looking for an appropriate JVM...
runjava: Checking for an appropriate JVM in JAVA_HOME...
runjava: Skipping... JAVA_HOME not set.
runjava: Checking JVM in the PATH: "/usr/lib/jvm/java-11-openjdk-"...
runjava: Found an appropriate JVM in the PATH: "/usr/lib/jvm/java-11-openjdk-"
runjava: Value of "/usr/lib/jvm/java-11-openjdk-" stored in configuration file.

Next, complete the OpenNMS setup using the following command.

/opt/opennms/bin/install -dis


Processing SystemIDMigratorOffline: Updates OpenNMS system ID to a random UUID.
- Running pre-execution phase
- Running execution phase
- Saving the execution state
- Running post-execution phase

Finished in 0 seconds
Upgrade completed successfully!

Start OpenNMS Service

Now, start the OpenNMS service and enable it to start at system reboot with the following command.

systemctl start opennms
systemctl enable opennms

You can now check the status of OpenNMS with the following command.

systemctl status opennms


● opennms.service - OpenNMS server
     Loaded: loaded (/usr/lib/systemd/system/opennms.service; disabled; vendor preset: disabled)
     Active: active (running) since Sat 2023-05-20 00:44:49 EDT; 2s ago
    Process: 6347 ExecStart=/opt/opennms/bin/opennms -s start (code=exited, status=0/SUCCESS)
    Process: 7330 ExecStartPost=/bin/sleep 3 (code=exited, status=0/SUCCESS)
   Main PID: 7329 (java)
      Tasks: 44 (limit: 4666)
     Memory: 313.7M
        CPU: 21.271s
     CGroup: /system.slice/opennms.service
             ├─7328 bash /opt/opennms/bin/opennms -s start
             └─7329 /usr/lib/jvm/java-11-openjdk- --add-modules=java.base,java.compiler,java.datatransfer,java.desktop,java.instrume>

Step 5 – Access OpenNMS Web UI

At this point, OpenNMS is started and listening on port 8980. You can verify it with the following command.

ss -antpl | grep 8980


LISTEN 0      50                      *:8980             *:*    users:(("java",pid=7329,fd=1197))

Now, open your web browser and access the OpenNMS web interface using the URL http://your-server-ip:8980/opennms. You should see the OpenNMS login page.

opennms login page

Provide the default username and password as admin/admin then click on the LOGIN button. You should see the OpenNMS dashboard on the following screen.

opennms dashboard


In this post, we explained how to install OpenNMS on Fedora. I hope you have now enough knowledge to install and set up OpenNMS in your environment easily. You can now install OpenNMS on VPS hosting from Atlantic.Net!


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