Installing on RedHat and CentOS

Danger

• If you decide to install Red Hat, you should have a licensed Red Hat version; otherwise, you won’t be able to install updates.
• The Red Hat ISO can be downloaded from https://developers.redhat.com/products/rhel/download for testing, but you must register first.

Tip

This installation guide works for other Red Hat-based distributions like Oracle Linux and Rocky Linux.

This guide has been validated with the following:

• RedHat 10
• Red Hat 9
• Red Hat 8
• Oracle Linux 7
• Rocky Linux 9
• CentOS Stream 9

Caution

If you use a proxy to access the Internet, please see Using the installer.

Preliminaries

Ensure you have enough disk space to install OpenKM and store the document repository:

$ df -h

Once verified, create the “openkm” user:

$ adduser openkm

If Java 17 is still not installed, please install the following:

$ yum install java-1.17.0-openjdk

Caution

If Java 17 packages are unavailable in your distro repositories, you must download and install them from Eclipse Temurin.

Caution

OpenKM currently only works with Java 17, so once the installation process is completed, verify the default version is Java 17:

# java -version
openjdk version "17.0.18" 2026-01-20
OpenJDK Runtime Environment (build 17.0.18.1+1)
OpenJDK 64-Bit Server VM (build 17.0.18.1+1, mixed mode, sharing)

Otherwise, set Java 17 as the default:

$ update-alternatives --config java

If you do not have any other preference for a database, we suggest installing MariaDB:

$ yum install mariadb-server

After that, enable and start the MariaDB service:

$ systemctl enable mariadb
$ systemctl start mariadb

Installing OpenKM

You can choose between installing OpenKM at “/home/openkm” or “/opt”. In any case, go to the selected path and download the installer.

It’s a text-based installer, so you must execute it from the console as root. This is because it needs to install package dependencies and configure OpenKM as a service:

$ java -jar OKMInstaller.jar

Remember to check Using the installer if you are using a proxy to access the Internet.

Caution

The installer will ask for an authorized user and password. If you don’t already have this information, please open a support ticket or contact your sales agent.

When the installation process has finished, please ensure that Java 17 is the default one:

$ java -version

Otherwise, set it as default:

$ update-alternatives --config java

Once verified, start the required services:

$ systemctl start xvfb openkm

You can verify the status of these services as follows:

$ systemctl status xvfb openkm

More info at:

• How do I turn SELinux off in Red Hat Enterprise Linux?
• Install Extra Packages for Enterprise Linux (EPEL)
• Remove the yum repo using yum

Enable remote access

Red Hat does not allow connections to port 8080 by default, so you need to open this port in the firewall:

$ firewall-cmd --zone=public --permanent --add-port=8080/tcp
$ firewall-cmd --reload

Post-installation checklist

To verify the installation was successful, please use this checklist:

• Verify the default Java is Java 17.
• Verify you can access OpenKM from another computer.
• Try to log in with the default okmAdmin / admin user and password.
• Upload a Word document and check if the thumbnail is generated and the preview is shown.

Troubleshooting

If you have a problem with thumbnail generation, please verify that you have the ImageMagick package installed and that the “convert” application works.

Download a sample image from Sample PNG Image and try to generate a thumbnail:

$ wget https://www.sample-videos.com/img/Sample-png-image-1mb.png
$ convert -thumbnail '80x80>' -background 'white' -flatten Sample-png-image-1mb.png sample-output.png