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Setting Up Barman for Local PostgreSQL Backups

Introduction

About This Guide

This guide explains how to install and configure Barman for backups on the same server as PostgreSQL. It is intended for demo or testing environments, not for production use.

In this article, I will explain how to install and configure Barman to perform backups of a PostgreSQL database on the same server. This method is not a best practice for production environments, but it can be very useful for demo environments, testing purposes, or emergency scenarios where simplicity is more important than scalability.

What is Barman?

Barman (Backup and Recovery Manager) is an open-source tool designed to manage backup and recovery operations for PostgreSQL databases.

With Barman, you can:

  • Take backups on the same server or a different backup server.

  • Manage backups from multiple PostgreSQL clusters.

  • Support various PostgreSQL versions.

  • Choose between streaming and rsync/ssh backup methods.

Why WAL Streaming Matters

WAL streaming ensures near-zero data loss (RPO=0), making it ideal for critical systems where minimal data loss is acceptable.

Installing Barman

System Requirements

  • PostgreSQL Version >= 10

  • Python >= 3.6

Server Setup Used

  • OS Version: Ubuntu 22.04.3

  • PostgreSQL Version: 13

  • PostgreSQL Data Directory: /database/PostgreSQL/13/main/

  • Barman Backup Directory: /pg_backup/

In this demo, Barman is installed on the same server as PostgreSQL.

Installation on Ubuntu/Debian

Ubuntu/Debian Install
sudo apt-get -y install barman
sudo apt-get -y install barman-cli

Installation on RHEL/Rocky Linux

RHEL/Rocky Install
sudo yum install -y barman
sudo yum install -y barman-cli

This installation will create a dedicated barman user that must be used to run backup and recovery operations.

PostgreSQL Configuration

You need two PostgreSQL users:

  • barman: for management and backup initiation.

  • streaming_barman: for WAL file streaming.

Create the users with:

Create PostgreSQL Users
createuser --superuser --replication -P barman
createuser --replication -P streaming_barman

Grant the necessary permissions for barman:

Grant Required Permissions
GRANT EXECUTE ON FUNCTION pg_start_backup(text, boolean, boolean) TO barman;
GRANT EXECUTE ON FUNCTION pg_stop_backup() TO barman;
GRANT EXECUTE ON FUNCTION pg_switch_wal() TO barman;
GRANT EXECUTE ON FUNCTION pg_create_restore_point(text) TO barman;
GRANT pg_read_all_settings TO barman;
GRANT pg_read_all_stats TO barman;

Update pg_hba.conf:

Update pg_hba.conf
host replication streaming_barman all md5

Check and update postgresql.conf:

postgresql.conf Settings
max_wal_senders = 10
max_replication_slots = 10

Reload PostgreSQL settings:

Reload PostgreSQL Config
SELECT pg_reload_conf();

Set up password authentication by creating a .pgpass file:

Create .pgpass File
su - barman
vim ~/.pgpass

Add credentials:

.pgpass Contents
localhost:*:*:barman:<password>
localhost:*:*:streaming_barman:<password>

Secure the .pgpass file:

Secure .pgpass
chmod 0600 ~/.pgpass

Finally, set up SSH key-based access between the barman and postgres users for rsync operations.

Barman Configuration

Create the backup directory and assign permissions:

Create Backup Directory
mkdir /pg_backup
chown barman:barman /pg_backup

Edit the main configuration file /etc/barman.conf:

/etc/barman.conf
barman_home = /pg_backup
recovery_options = get-wal
reuse_backup = link
compression = gzip
retention_policy_mode = auto
retention_policy = RECOVERY WINDOW OF 1 days
wal_retention_policy = main

Configure your server under /etc/barman.d/pg.conf:

/etc/barman.d/pg.conf
[pg]
description = "Example of PostgreSQL Database (via SSH) and WAL Streaming"
ssh_command = ssh postgres@localhost
conninfo = host=localhost user=barman dbname=postgres
backup_method = rsync
backup_options = concurrent_backup

streaming_conninfo = host=localhost user=streaming_barman
streaming_archiver = on
create_slot = auto
slot_name = barman
streaming_archiver_name = barman_receive_wal
streaming_archiver_batch_size = 50

Test the configuration:

Test Barman Config
barman cron
barman check pg

Ensure all status outputs are OK.

Taking Backups

Manually trigger a backup:

Manual Backup
barman backup pg

List existing backups:

List Backups
barman list-backup pg

Backup directory structure:

  • base/ : Full base backups

  • wals/ : Archived WAL files

  • stream/ : Streaming WAL files

Recovery from Backup

In the event of a failure, you can recover the PostgreSQL server from the backup.

Stop the PostgreSQL service:

Stop PostgreSQL
sudo systemctl stop postgresql

Recover the latest backup:

Recover Latest Backup
barman recover --remote-ssh-command 'ssh postgres@localhost' pg latest /database/PostgreSQL/13/main/

Or recover a specific backup:

Recover Specific Backup
barman recover --remote-ssh-command 'ssh postgres@localhost' pg 20231211T110303 /database/PostgreSQL/13/main/

After recovery, edit the postgresql.auto.conf file and set the restore command:

Set Restore Command
restore_command = 'barman-wal-restore -P -U barman localhost pg %f %p'

Then start the PostgreSQL service:

Start PostgreSQL
sudo systemctl start postgresql

Important Note

Always verify the restored database carefully before putting it back into production.

Automating Backups with Cron

To schedule automatic daily backups, edit /etc/cron.d/barman and add:

Cron Backup Job
0 23 * * * barman [ -x /usr/bin/barman ] && /usr/bin/barman backup pg

This example runs backups every day at 23:00.

Notes

Configuration Files Not Backed Up

Barman does not back up the following files:

  • postgresql.conf

  • pg_hba.conf

  • pg_ident.conf

Always manually back up your configuration files if needed.

Conclusion

This guide demonstrates how Barman can be configured on a single server to perform PostgreSQL backups easily.

While not recommended for production environments, this approach is very handy for demos, training labs, or testing backup strategies.

In future posts, we will explore advanced recovery options and cross-server backup configurations!

Written by: Ruchan Yalçın | GitHub