How to Install and Configure Postgres 13 on CentOS 8

In this guide we are going to install PostgreSQL 13 on CentOS 8 / Rocky Linux 8. This will also work in RHEL 8 and its derivatives.

Heads-up (reviewed July 2026): CentOS Linux 8 reached end of life on December 31, 2021, and PostgreSQL 13 reached end of life on November 13, 2025 — both are now unsupported and no longer receive security updates. The steps below still work and apply unchanged to Rocky Linux 8 and AlmaLinux 8, the recommended drop-in replacements for CentOS 8 (supported until 2029). For a new deployment, prefer a currently supported PostgreSQL release (14–18) — see How to Install and Configure Postgres 17 on Rocky/Alma Linux 9. If you are still on CentOS 8, see How to Migrate from CentOS 8 to Rocky Linux 8.

PostgreSQL, is a powerful, open source object-relational database system with over 30 years of active development that has earned it a strong reputation for reliability, feature robustness, and performance. Postgres, is a free and open-source relational database management system emphasizing extensibility and SQL compliance. It was originally named POSTGRES, referring to its origins as a successor to the Ingres database developed at the University of California, Berkeley. PostgreSQL is used as the primary data store or data warehouse for many web, mobile, geospatial, and analytics applications. PostgreSQL can store structured and unstructured data in a single product.

Check these also:

Prerequisites

To follow along, ensure you have the following:

Centos 8 / Rocky Linux 8 / RHEL 8 based server
Root access to the server or user with root access
Internet access from the server
Basic knowledge of Linux terminal

Ensure the server is up to date
Installing and starting Postgres Server
PostgreSQL Roles and Databases Authentication Methods
Connecting to postgres database
Configuring postgres 13 instance for remote access
User management

1. Ensure the server is up to date

Before proceeding, let us ensure that our server has up to date packages. Use this command:

$ sudo dnf -y update
Last metadata expiration check: 2:52:07 ago on Wed 06 Oct 2021 01:26:21 AM UTC.
Dependencies resolved.
Nothing to do.
Complete!

2. Installing and starting Postgres Server

List out the available streams for the postgresql module using the dnf command:

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dnf module list postgresql

Output:

# dnf module list postgresql

Name                    Stream              Profiles                        Summary
postgresql              9.6                 client, server [d]              PostgreSQL server and client module
postgresql              10 [d]              client, server [d]              PostgreSQL server and client module
postgresql              12                  client, server [d]              PostgreSQL server and client module
postgresql              13                  client, server [d]              PostgreSQL server and client module

Hint: [d]efault, [e]nabled, [x]disabled, [i]nstalled

On Rocky Linux 8 / AlmaLinux 8 today the module also offers newer streams (14, 15, and 16). List them with dnf module list postgresql and swap 13 for a supported stream if you don’t specifically need PostgreSQL 13.

the module marked with [d] is the default thus installing postgres without specifying Stream will install that. In our case the following command installs postgres 10

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sudo dnf install @postgresql

This is the installed version

$ sudo dnf list installed | grep postgres
postgresql.x86_64                   10.17-1.module_el8.4.0+823+f0dbe136     @appstream
postgresql-server.x86_64            10.17-1.module_el8.4.0+823+f0dbe136     @appstream

Since that is not the package I want, I am going to uninstall it with this

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sudo dnf erase -y @postgresql

Now let us install postgresql 13. We will first reset the postgresql module to ensure there is none installed.

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sudo dnf module reset postgresql

sudo dnf install @postgresql:13

Let’s also install the contrib package which provides several additional features for the PostgreSQL database system.

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sudo dnf install postgresql-contrib

Once the installation is complete, initialize the PostgreSQL database with the following command:

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sudo postgresql-setup --initdb

Output:

 * Initializing database in '/var/lib/pgsql/data'
 * Initialized, logs are in /var/lib/pgsql/initdb_postgresql.log

Start the PostgreSQL service and enable it to start on boot:

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sudo systemctl enable --now postgresql

Check status of the db

# systemctl status postgresql
&#x25CF; postgresql.service - PostgreSQL database server
   Loaded: loaded (/usr/lib/systemd/system/postgresql.service; enabled; vendor preset: disabled)
   Active: active (running) since Thu 2021-08-05 08:15:07 UTC; 7s ago
  Process: 68683 ExecStartPre=/usr/libexec/postgresql-check-db-dir postgresql (code=exited, status=0/SUCCESS)
 Main PID: 68686 (postmaster)
    Tasks: 8 (limit: 23506)
   Memory: 17.3M
   CGroup: /system.slice/postgresql.service
           &#x251C;&#x2500;68686 /usr/bin/postmaster -D /var/lib/pgsql/data
           &#x251C;&#x2500;68687 postgres: logger
           &#x251C;&#x2500;68689 postgres: checkpointer
           &#x251C;&#x2500;68690 postgres: background writer
           &#x251C;&#x2500;68691 postgres: walwriter
           &#x251C;&#x2500;68692 postgres: autovacuum launcher
           &#x251C;&#x2500;68693 postgres: stats collector
           &#x2514;&#x2500;68694 postgres: logical replication launcher

Aug 05 08:15:07 prod-db systemd[1]: Starting PostgreSQL database server...
Aug 05 08:15:07 prod-db postmaster[68686]: 2021-08-05 08:15:07.650 UTC [68686] LOG:  redirecting log output to logging collector process
Aug 05 08:15:07 prod-db postmaster[68686]: 2021-08-05 08:15:07.650 UTC [68686] HINT:  Future log output will appear in directory "log".
Aug 05 08:15:07 prod-db systemd[1]: Started PostgreSQL database server.

The Active: active (running) shows that our postgres server is up and runnig as expected.

Verify the installation by connecting to the PostgreSQL database server and print its version:

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sudo -u postgres psql -c "SELECT version();"

Output:

                                                  version
------------------------------------------------------------------------------------------------------------
 PostgreSQL 13.3 on x86_64-redhat-linux-gnu, compiled by gcc (GCC) 8.3.1 20191121 (Red Hat 8.3.1-5), 64-bit
(1 row)

3. PostgreSQL Roles and Databases Authentication Methods

PostgreSQL uses a concept called roles to handle client authentication and authorization. By default, Postgres is set up to use ident authentication, meaning that it associates Postgres roles with a matching Unix/Linux system account. If a role exists within Postgres, a Unix/Linux username with the same name is able to sign in as that role.

The installation procedure created a user account called postgres that is associated with the default postgres role. In order to use PostgreSQL, you can log in to that account.

PostgreSQL supports multiple authentication methods . The most commonly-used methods are:

Trust – A role can connect without a password, as long as the conditions defined in the pg_hba.conf are met.
Password – A role can connect by providing a password. The passwords can be stored as scram-sha-256, md5, and password (clear-text).
Ident – Only supported on TCP/IP connections. It works by obtaining the client’s operating system user name, with an optional user name mapping.
Peer – Same as Ident, but it is supported on local connections only.

4. Connecting to postgres database

There are a number of ways to connect to the postgres server as the postgres user:

1. By switching to the postgres user

Switch over to the postgres account on your server by typing:

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sudo -i -u postgres

You can now access a Postgres prompt immediately by typing psql:

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[postgres@db-server ~]$ psql
psql (13.3)
Type "help" for help.

postgres=#

This will log you into the PostgreSQL prompt, and from here you are free to interact with the database management system right away.

2. By running the command as the postgres user

Use this to run the command directly as the postgres user using sudo:

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sudo -u postgres psql

5. Configuring postgres 13 instance for remote access

To achieve this, we will modify postgres configuration files. We need to open the files and adjust the configs as required.

The PostgreSQL 13 client authentication config file is located at /var/lib/pgsql/data/pg_hba.conf.

Change peer identification to trust:

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sed -i '/^local/s/peer/trust/' /var/lib/pgsql/data/pg_hba.conf

Change ident identification to md5

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sed -i '/^host/s/ident/md5/' /var/lib/pgsql/data/pg_hba.conf

Add a block to allow access from everywhere:

Add this content to the file /var/lib/pgsql/data/pg_hba.conf

host    all             all             0.0.0.0/0                md5

Security note: 0.0.0.0/0 opens the server to every host — fine for a lab, but for anything internet-facing restrict the CIDR to the networks you trust (or keep Postgres behind a firewall/VPN). Prefer scram-sha-256 over md5 for password storage: set password_encryption = scram-sha-256 in postgresql.conf, use scram-sha-256 instead of md5 in the pg_hba.conf lines above, and reset each user’s password so it is re-hashed.

Ensure PostgreSQL is listening on all interfaces. Add this line to the config here /var/lib/pgsql/data/postgresql.conf

listen_addresses = '*'

Enable and restart postgresql server to reload the configs

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sudo systemctl restart postgresql
sudo systemctl enable postgresql

6. User management

Create Super user

Let us create a user with super user privileges that we can use to administer postgres.

Connect to the DB as the postgres role

$ sudo -u postgres psql
psql (13.3)
Type "help" for help.

postgres=#

Create super user with name root:

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CREATE ROLE root WITH LOGIN SUPERUSER CREATEDB CREATEROLE PASSWORD 'passwordhere';

Check the user if its been created and granted necessary privileges:

postgres=# CREATE ROLE root WITH LOGIN SUPERUSER CREATEDB CREATEROLE PASSWORD 'MrBpR89Yskv3hofGLP';
CREATE ROLE
postgres=# \du
                                   List of roles
 Role name |                         Attributes                         | Member of
-----------+------------------------------------------------------------+-----------
 postgres  | Superuser, Create role, Create DB, Replication, Bypass RLS | {}
 root      | Superuser, Create role, Create DB                          | {}

Managing Application Users

Use this to create a database, create a user and grant that user all access to that database:

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create database app_db_name;
create user app_user with encrypted password 'dbpassword';
grant all privileges on database app_db_name to app_user;

On PostgreSQL 15 and newer, database-level privileges no longer grant rights on the public schema. On those versions also run GRANT ALL ON SCHEMA public TO app_user; (connected to app_db_name) so the user can create objects. On PostgreSQL 13 this extra grant is not required.

Checkout this comprehensive guide on user and permission management in postgres here.

Connecting to the instance from remote host

Use this command to connect to the postgres instance from local machine:

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psql 'postgres://<username>:<password>@<host>:<port>/<db>?sslmode=disable'

# like
psql 'postgres://root:[email protected]:5432/postgres?sslmode=disable'

Conclusion

Up to this point we have managed to install PostgreSQL 13 on a CentOS 8 / Rocky Linux 8 server, do some basic configurations then do basic user management.