pgBackRest — Reliable PostgreSQL Backup and Restore

Introduction

pgBackRest is a backup and restore tool designed specifically for PostgreSQL. It handles the complexity of WAL archiving, parallel backup compression, and multi-repository storage so database administrators can implement reliable disaster recovery without writing custom scripts.

What pgBackRest Does

• Creates full, incremental, and differential backups of PostgreSQL clusters
• Archives WAL segments for point-in-time recovery (PITR)
• Compresses backups in parallel using multiple CPU cores
• Encrypts backups at rest with AES-256-CBC
• Stores backups on local disk, S3, Azure Blob, or Google Cloud Storage

Architecture Overview

pgBackRest runs as a standalone process alongside PostgreSQL. It communicates with the database via the PostgreSQL protocol for backup coordination and uses file-level copy for data transfer. WAL archiving integrates through the archive_command configuration. The tool maintains a manifest of all backed-up files to enable efficient incremental backups that only transfer changed pages.

Self-Hosting & Configuration

• Install via package manager (apt, yum) or compile from source
• Create a stanza configuration in /etc/pgbackrest/pgbackrest.conf
• Set archive_command in postgresql.conf to route WAL to pgBackRest
• Configure retention policies for full and differential backup counts
• Add S3 or GCS credentials for off-site backup storage

Key Features

• Delta restore that only replaces files that differ from the backup
• Backup verification with checksum validation against the PostgreSQL catalog
• Asynchronous WAL push and pull for high-throughput archiving
• Multiple backup repositories for redundancy across storage providers
• Standby server backup support to offload backup I/O from the primary

Comparison with Similar Tools

• pg_dump — logical backup only, no incremental or PITR support
• Barman — similar feature set but Python-based with different architecture
• WAL-G — Go-based tool focused on cloud storage, less mature retention management
• pg_basebackup — built-in but lacks compression, encryption, and incremental support
• Borg + pg_dump — generic backup with PostgreSQL wrapper, not database-aware

FAQ

Q: Does pgBackRest support PostgreSQL streaming replication? A: Yes. It can back up from a standby replica to avoid impacting primary performance.

Q: How fast is incremental backup? A: Incremental backups only transfer changed blocks, making them significantly faster than full backups for large databases.

Q: Can I restore to a specific point in time? A: Yes. Specify a target timestamp, transaction ID, or LSN for point-in-time recovery using archived WAL segments.

Q: What PostgreSQL versions are supported? A: pgBackRest supports PostgreSQL 9.0 through the latest release, with full feature support from version 9.4 onward.

Sources

• https://github.com/pgbackrest/pgbackrest
• https://pgbackrest.org