Install PostgreSQL client and server sudo apt -y install postgresql Create an opennms database user and password sudo -u postgres createuser -P opennms You must provide a password for the opennms database user. This guide uses YOUR-OPENNMS-PASSWORD as a placeholder. Please set a secure password. Create an empty database and set the owner to the opennms user sudo -u postgres createdb -O opennms opennms Set a password for PostgreSQL superuser sudo -u postgres psql -c "ALTER USER postgres WITH PASSWORD 'YOUR-POSTGRES-PASSWORD';" Change YOUR-POSTGRES-PASSWORD to a secure one. The superuser is required to initialize and change the database schema for installation and updates.