Bind Volumes vs. Named Volumes: Which one do you need?

If you are working with Docker, you need to know which type of volume to use for your application. There are two main types: Bind Volumes and Named Volumes.

1. Bind Volumes (The Two-Way Mirror) Imagine you are building a web app and consistently adding new features. Instead of rebuilding the image every time you update your code, you use a Bind Volume. You attach a folder on your laptop directly to a folder inside the container. If you change the code on your laptop, it automatically reflects inside the container.

Example:

1. Create a folder on your laptop

mkdir -p $(pwd)/laptop-dir

2. Run a container and "Bind" that specific folder

docker run -d --name bind-test -v $(pwd)/laptop-dir:/data alpine sh -c "echo 'Data from Mac' > /data/hello.txt && sleep 1000"

Here
-v: This handles the volume work.
/data: The folder inside the container.
sh -c: This creates a shell to talk to the Linux kernel and run our commands.
sleep 1000: Since a container only runs as long as the main process is alive, we use sleep to give us time to see the file on our laptop before the process ends.

1. Named Volumes (The Persistent Vault) For Named Volumes, the Docker engine creates storage internally. You use this for important things like production databases. If a container is deleted, the data usually goes with it—but not if you use a Named Volume. You can simply attach that same storage to a new container.

Example:

1. Create the volume

docker volume create my-sre-vault

2. Use it in a container

docker run -d --name temp-db -v my-sre-vault:/data alpine sh -c "echo 'Hemant was here' > /data/file.txt && sleep 1000"

3. Delete the container

docker rm -f temp-db

4. Prove the data is still there in a new container

docker run --rm -v my-sre-vault:/data alpine cat /data/file.txt

Even after deleting the container, we can still get the data. That is the beauty of a Named Volume—it saves your data even if the container is gone.

The Summary:
Use Bind Volumes for things like source code or files that change often during development.
Use Named Volumes for private, stable things like databases where data persistence is a must.