Backups

The database is backed up using Restic, which provides incremental, encrypted, deduplicated backups. Each backup is compressed with zstd before being stored. Because Restic deduplicates across snapshots, frequent backups are storage-efficient.

The backup scripts live in deploy/ in the dodeka repository. See deploy/BACKUP.md for the full reference.

How it works

1. The SQLite database is exported with VACUUM INTO (produces a clean, compacted copy)
2. The export is compressed with zstd --rsyncable
3. The compressed file is uploaded to a Restic repository at /mnt/backup/restic

Each snapshot is tagged (e.g. db_dodeka, env_production) so you can filter when listing or restoring.

Setup

See server from scratch how to set it up on the server.

Setting up the cron job

The cron script (dodeka-db-cron.sh) runs a backup and then prunes old snapshots according to the retention policy. A pre-made crontab file is provided that backs up both production and demo every 12 minutes (with a 6-minute offset so they don’t overlap).

Install it with:

crontab ~/dodeka/deploy/dodeka_crontab

This replaces your current crontab. The schedule is:

• Production: every 12 minutes (:00, :12, :24, :36, :48)
• Demo: every 12 minutes at 6-minute offset (:06, :18, :30, :42, :54)

Output is appended to /home/backend/log/backup.log.

Retention policy

The cron script automatically prunes old snapshots with the following retention:

Manual backup

~/dodeka/deploy/dodeka-db-backup.sh production
~/dodeka/deploy/dodeka-db-backup.sh demo

Restore

# Restore from same environment
~/dodeka/deploy/dodeka-db-restore.sh production

# Clone production data to demo
~/dodeka/deploy/dodeka-db-restore.sh demo --from production

The restore script will:

1. List available snapshots and ask you to pick one (or type latest)
2. Stop the backend service
3. Back up the current database (tagged pre-restore, so you can undo)
4. Download and decompress the selected snapshot
5. Replace the database file (clearing WAL/SHM files)
6. Restart the service

Listing snapshots

# All dodeka snapshots
restic -r /mnt/backup/restic --password-file /mnt/backup/.restic-password snapshots --tag db_dodeka

# Only production
restic -r /mnt/backup/restic --password-file /mnt/backup/.restic-password snapshots --tag env_production