Step-by-step implementation Filesystem Snapshots in PostgreSQL

Implementing filesystem snapshots in PostgreSQL is an efficient way to back up large databases. Here's a step-by-step guide:

1. Ensure Filesystem Support:

   • Confirm that your filesystem (e.g., ZFS, Btrfs, LVM) supports snapshots.

2. Configure PostgreSQL for WAL Archiving:

   • Set wal_level to replica or higher in postgresql.conf.
   • Configure continuous archiving of WAL files using archive_mode and archive_command.

3. Prepare for Snapshot:

   • Reduce or pause database write activities if possible.
   • Run SELECT pg_start_backup('snapshot_label'); in PostgreSQL. This creates a consistent state for the snapshot.

4. Create Filesystem Snapshot:

   • Immediately create a snapshot of the filesystem or volume where the PostgreSQL data directory resides. The command varies based on the filesystem (e.g., lvcreate --snapshot for LVM).

5. Complete the Backup:

   • Resume normal database operations.
   • Run SELECT pg_stop_backup(); in PostgreSQL. This marks the end of the backup and ensures any remaining WAL files are archived.

6. Restoring from Snapshot:

   • To restore, replace the data directory with the snapshot.
   • Use WAL files for point-in-time recovery if necessary.

7. Test Your Backup and Restore Process:

   • Regularly test the backup and restore procedure to ensure it works as expected.

8. Automate the Process (Optional):

   • Consider scripting the process for regular automated backups.

Remember, while filesystem snapshots are efficient, they should be part of a comprehensive backup strategy that includes regular WAL archiving and testing of the restore process.

More topics on PostgreSQL:

• https://minervadb.xyz/comparing-storage-mechanisms-oracles-pctfree-pctused-and-row-migration-vs-postgresqls-mvcc-and-tuple-management/

• https://minervadb.xyz/cardinality-in-postgresql-the-key-to-query-performance-optimization/

• https://minervadb.xyz/mastering-data-type-conversion-practical-applications-of-the-postgresql-cast-operator/

• https://minervadb.xyz/unleashing-the-power-of-postgresql-a-comprehensive-guide-to-sql-aggregation-functions-and-their-use-cases/