How to make Docker data persistent across reboots

How to make Docker data persistent: The new container best practice is to create folders on the host to store the app’s data. This assumes you are using docker compose YAML files and docker run commands

mkdir -p ~/myapp/data  # generic example

With docker-compose.yml:

services:
  myapp:  # generic example
    image: myimage:latest   #generic example
    restart: unless-stopped
    volumes:
      - ./data:/var/lib/myapp   # <- app’s data dir inside container.  ./ = current directory - home, in this case

Bring up the containers.

docker compose up -d

Verify it’s persistent - using [adguardhome] as the container name

docker inspect adguardhome --format '{{range .Mounts}}{{println .Source "->" .Destination}}{{end}}'

You should see your host path mapped to the container path.

Existing container (already running, but NOT persistent yet) Create host folders:

mkdir -p ~/myapp/data  # generic example

Example: Using Adguard as the example.

mkdir -p ~/adguard-home/work
mkdir -p ~/adguard-home/conf

Copy data out of the running container (so you don’t lose current settings):

docker cp myapp:/var/lib/myapp ~/myapp/  # generic example

Example: Using Adguard as the example.

docker cp adguardhome:/opt/adguardhome/work ~/adguard-home/
docker cp adguardhome:/opt/adguardhome/conf ~/adguard-home/
sudo chown -R $USER:$USER ~/adguard-home/work ~/adguard-home/conf

Edit docker-compose.yml to add the volumes:

volumes:
  - ./work:/opt/adguardhome/work
  - ./conf:/opt/adguardhome/conf

Then:

cd ~/adguard-home
docker compose down
docker compose up -d

Verify mounts (same inspect command as above).

docker inspect adguardhome --format '{{range .Mounts}}{{println .Source "->" .Destination}}{{end}}'

Notes you’ll need exactly once Pick the right container path: every app has a data dir; check its docs or container README. (AdGuard: /opt/adguardhome/work and /opt/adguardhome/conf.)

Permissions: if you hit “permission denied” when backing up or copying, fix ownership on the host:

sudo chown -R $USER:$USER ~/myapp

Backups: once persistent, back up the host folders (e.g., with your rsync command).

That’s it. New or existing, the core idea is the same: bind‑mount a host folder into the container’s data directory so the data lives outside the container and survives rebuilds/reboots.