Demonstration on how Docker Volumes & Data Persistence

Step 1: Create a Docker Volume

docker volume create mydata

Explanation:This creates a persistent storage location managed by Docker.

Step 2: Run a Container Using the Volume

docker run -it --name testcontainer -v mydata:/data ubuntu

Explanation:

• -v mydata:/data → Mount the volume inside container at /data

• ubuntu → Runs Ubuntu container

• /data → Any files created here will go into the volume

Step 3: Create a File Inside the Volume

Inside the container, type:

echo "Hello Docker Volume" > /data/info.txt

Check the file:

cat /data/info.txt

You will see:

Hello Docker Volume

Step 4: Exit the Container

Exit:

exit

Step 5: Remove the Container

docker rm testcontainer

Important:We removed the container, BUT the volume still exists.

Step 6: Run a New Container With Same Volume

docker run -it --name newcontainer -v mydata:/data ubuntu

Now check the data:

cat /data/info.txt

You will see:

Hello Docker Volume

Conclusion: Data Persistence

Container deleted

New container created

Data STILL EXIST

Because volumes are persistent and managed by Docker, not tied to any single container.

What You Learned

Feature	Meaning
Volume	Persistent storage created by Docker
Mounting	Attaching volume to container path
Data Persistence	Data survives even after container deletion