Backups

The nexus-backup script is installed to /usr/local/bin/nexus-backup by the installer. It snapshots both the PostgreSQL database and the uploads directory in one command.

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Running a backup

sudo nexus-backup

The script must be run as root. It produces two files in /opt/nexus-backups/:

File	Contents
db_YYYYMMDD_HHMMSS.sql.gz	Compressed PostgreSQL dump of the nexus_prod database
uploads_YYYYMMDD_HHMMSS.tar.gz	Compressed archive of /opt/nexus-data/uploads/

The backup directory is created automatically if it doesn’t exist.

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How the backup works

Database: The script runs pg_dump inside the running database container (nexus-db-1) and pipes the output through gzip:

docker exec nexus-db-1 pg_dump -U nexus nexus_prod | gzip > /opt/nexus-backups/db_TIMESTAMP.sql.gz

Uploads: The script archives the uploads directory:

tar -czf /opt/nexus-backups/uploads_TIMESTAMP.tar.gz -C /opt/nexus-data uploads/

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Retention policy

The script keeps the 10 most recent backups of each type and automatically deletes older ones. With daily backups, this gives 10 days of retention.

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Automating backups

Schedule nexus-backup with cron to run automatically. To back up daily at 2 AM:

sudo crontab -e

Add:

0 2 * * * /usr/local/bin/nexus-backup >> /var/log/nexus-backup.log 2>&1

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Restoring from a backup

Restoring the database

1. Stop the Nexus application container so no writes occur during restore:

cd /opt/nexus
docker compose -f docker-compose.prod.yml stop app

2. Restore the database dump into the running database container:

gunzip -c /opt/nexus-backups/db_TIMESTAMP.sql.gz | docker exec -i nexus-db-1 psql -U nexus -d nexus_prod

3. Restart the application:

docker compose -f docker-compose.prod.yml start app

Restoring uploads

tar -xzf /opt/nexus-backups/uploads_TIMESTAMP.tar.gz -C /opt/nexus-data

This restores into /opt/nexus-data/uploads/, overwriting existing files.

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What is not backed up

nexus-backup covers the database and user-uploaded files. It does not back up:

• /opt/nexus/.env — back this up manually and store it securely. It contains all secrets and is irreplaceable.
• /opt/nexus/Caddyfile — back this up if you’ve added custom site blocks.
• The Nexus application code at /opt/nexus/ — this is recreatable by running the installer or nexus-update, but consider backing it up if you’ve made local customisations.