🔄 How to Safely Back Up & Restore Docker Compose Data

When you’re running apps with Docker Compose, your data is the heart and soul of your services—databases, media files, configurations, and more. Without a solid backup and restore plan, a simple mistake (or disk failure!) can lead to a world of pain. Here’s a step-by-step guide to properly back up and restore data from Docker Compose environments, the right way.

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Why Back Up Docker Compose Volumes and Data?

By default, Docker containers are ephemeral. Persistent data lives in volumes or bind mounts—which need explicit backup. Databases (Postgres, MySQL), app uploads, and configs are often stored here.

If you lose a volume, your critical data is gone.

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🗂️ What Should You Back Up?

1. Docker Volumes: Contents of named volumes managed by Docker.
2. Bind Mounts: Data mapped to host folders.
3. Database Dumps: Logical (SQL) dumps for easy portability & restore.
4. Configs: Your docker-compose.yml, .env, TLS keys, and other setup files.

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🚀 Step-by-Step: Back Up Docker Compose Data

1️⃣ Identify Your Data

First, look at your docker-compose.yml for volumes/bind mounts:

services:
  db:
    image: postgres
    volumes:
      - pgdata:/var/lib/postgresql/data

volumes:
  pgdata:

Here the named volume is pgdata.

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2️⃣ Stop the Compose Stack (Recommended)

This ensures consistent backups (especially for databases):

docker compose down

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3️⃣ Back Up Docker Volumes

List all local volumes:

docker volume ls

To back up a volume (e.g., pgdata), run:

docker run --rm 
  -v pgdata:/volume 
  -v $(pwd):/backup 
  busybox 
  tar czvf /backup/pgdata_backup.tar.gz -C /volume .

• This creates a pgdata_backup.tar.gz in your current directory.
• More on managing Docker volumes

Repeat for each volume you want to back up.

Bind mounts?

Just copy the folder on the host:

cp -a /absolute/path/to/mount /your/backup/location

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4️⃣ Logical Database Backups (Recommended for Portability)

For MySQL:

docker exec <db_container> mysqldump -u root -p<pass> <database> > mysql_backup.sql

For PostgreSQL:

docker exec -t <db_container> pg_dump -U <user> <db> > pg_backup.sql

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💾 Restoring Your Data

1️⃣ Restore a Docker Volume from Backup

Create the volume if needed:

docker volume create pgdata

Unpack the tarball:

docker run --rm 
  -v pgdata:/volume 
  -v $(pwd):/backup 
  busybox 
  tar xzvf /backup/pgdata_backup.tar.gz -C /volume

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2️⃣ Restore a Bind Mount

Just reverse your earlier copy:

cp -a /your/backup/location /absolute/path/to/mount

3️⃣ Restore Database from Dump

For MySQL:

docker exec -i <db_container> mysql -u root -p<pass> <database> < mysql_backup.sql

For PostgreSQL:

cat pg_backup.sql | docker exec -i <db_container> psql -U <user> <db>

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4️⃣ Bring the Stack Up

docker compose up -d

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🔐 Pro Tips

• Automate backups! Use cron or a backup script.
• Store backups offsite (cloud, external drive, etc).
• Test your backups regularly! A backup you can’t restore isn’t a backup.

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📚 Resources

• Backup, restore, or migrate data volumes | Docker Docs
• Docker Compose file reference
• Best practices for backing up Docker containers – Docker Blog
• Backing up Docker volumes to S3 (article)

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