Step-by-step implementation Filesystem Snapshots in PostgreSQL

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Shiv Iyer
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Step-by-step implementation Filesystem Snapshots in PostgreSQL

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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:

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