Creating and managing volumes in Docker - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the command to create a Docker volume named mydata.

Docker

docker volume [1] mydata

Drag options to blanks, or click blank then click option'

Ainspect

Brm

Ccreate

Dlist

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'rm' instead of 'create' deletes volumes instead of creating.

Using 'list' shows volumes but does not create.

Using 'inspect' shows details but does not create.

The docker volume create command creates a new volume. Here, mydata is the volume name.

2fill in blank

medium

Complete the command to list all Docker volumes on your system.

Docker

docker volume [1]

Drag options to blanks, or click blank then click option'

Acreate

Bls

Crm

Dinspect

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'create' tries to make a new volume instead of listing.

Using 'rm' deletes volumes instead of listing.

Using 'inspect' shows details of one volume, not the list.

The docker volume ls command lists all volumes available on your system.

3fill in blank

hard

Fix the command to remove a Docker volume named olddata.

Docker

docker volume [1] olddata

Drag options to blanks, or click blank then click option'

Arm

Bls

Ccreate

Dinspect

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'create' tries to make a volume instead of deleting.

Using 'ls' lists volumes but does not delete.

Using 'inspect' shows details but does not delete.

The docker volume rm command removes a volume. Here, olddata is the volume to delete.

4fill in blank

hard

Fill both blanks to inspect details of a Docker volume named myvolume.

Docker

docker volume [1] [2]

Drag options to blanks, or click blank then click option'

Ainspect

Brm

Cmyvolume

Dls

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'rm' deletes the volume instead of inspecting.

Using 'ls' lists volumes but does not inspect.

Swapping the order of command and volume name.

The command docker volume inspect myvolume shows detailed information about the volume named myvolume.

5fill in blank

hard

Fill all three blanks to run a container named webapp that uses a volume named data_vol mounted at /app/data.

Docker

docker run -d --name [1] -v [2]:[3] nginx

Drag options to blanks, or click blank then click option'

Awebapp

Bdata_vol

C/app/data

Dmycontainer

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up container name and volume name.

Using a wrong path for the mount point.

Forgetting the colon ':' between volume and path.

This command runs a container named webapp using the volume data_vol mounted inside the container at /app/data. The -v option connects the volume to the container path.

Practice

1. What is the main purpose of Docker volumes?

easy

A. To manage network connections between containers

B. To speed up container startup time

C. To create new containers automatically

D. To store data outside of containers so it is not lost when containers stop

Solution

1. Step 1: Understand what volumes do

   Volumes store data outside the container's writable layer, so data persists even if the container is removed.

2. Step 2: Compare options

   Only To store data outside of containers so it is not lost when containers stop describes this purpose correctly. Other options describe unrelated features.

3. Final Answer:

   To store data outside of containers so it is not lost when containers stop -> Option D

4. Quick Check:

   Volumes keep data safe outside containers = A [OK]

Hint: Volumes keep data safe outside containers [OK]

Common Mistakes:

• Confusing volumes with container networking
• Thinking volumes speed up container start
• Assuming volumes create containers

2. Which command correctly creates a Docker volume named mydata?

easy

A. docker volume new mydata

B. docker volume create mydata

C. docker create volume mydata

D. docker volume add mydata

Solution

1. Step 1: Recall Docker volume creation syntax

   The correct command to create a volume is docker volume create [name].

2. Step 2: Match options to syntax

   Only docker volume create mydata matches the correct syntax exactly.

3. Final Answer:

   docker volume create mydata -> Option B

4. Quick Check:

   Use 'docker volume create' = C [OK]

Hint: Use 'docker volume create' to make volumes [OK]

Common Mistakes:

• Using wrong command order like 'docker create volume'
• Using non-existent commands like 'docker volume new'
• Confusing 'add' with 'create'

3. What is the output of the command docker volume ls after creating two volumes named vol1 and vol2?

medium

A. Lists volumes including vol1 and vol2

B. Lists all containers running

C. Shows detailed info about vol1 only

D. Deletes volumes vol1 and vol2

Solution

1. Step 1: Understand what 'docker volume ls' does

   This command lists all Docker volumes available on the system.

2. Step 2: Interpret the scenario

   After creating volumes vol1 and vol2, the command will list both volumes among others.

3. Final Answer:

   Lists volumes including vol1 and vol2 -> Option A

4. Quick Check:

   'docker volume ls' lists volumes = A [OK]

Hint: 'docker volume ls' shows all volumes [OK]

Common Mistakes:

• Confusing volume list with container list
• Expecting detailed info instead of list
• Thinking it deletes volumes

4. You run docker volume rm myvolume but get an error saying the volume is in use. What should you do to fix this?

medium

A. Restart Docker daemon and try removing again

B. Rename the volume before removing it

C. Stop and remove containers using the volume, then remove the volume

D. Use docker volume create again to overwrite it

Solution

1. Step 1: Understand volume usage error

   Docker prevents removing volumes that are still attached to running or stopped containers.

2. Step 2: Fix by stopping/removing containers

   You must stop and remove containers using the volume before deleting the volume itself.

3. Final Answer:

   Stop and remove containers using the volume, then remove the volume -> Option C

4. Quick Check:

   Remove containers before volumes in use = D [OK]

Hint: Remove containers using volume before deleting volume [OK]

Common Mistakes:

• Trying to rename volume to delete it
• Recreating volume instead of removing
• Restarting Docker daemon without stopping containers

5. You want to create a Docker container that uses a volume named appdata to persist data at /data inside the container. Which command correctly does this?

hard

A. docker run --mount source=appdata,target=/data myimage

B. docker run -v /appdata:/data myimage

C. docker run -v /data appdata myimage

D. docker run --volume /data:appdata myimage

Solution

1. Step 1: Understand volume mounting syntax

   The recommended syntax for mounting a named volume is docker run --mount source=volume_name,target=container_path image. The shorthand -v volume_name:container_path also works, but paths starting with / indicate bind mounts from the host.

2. Step 2: Compare options

   docker run -v /appdata:/data myimage performs a bind mount from the host directory /appdata, not the named volume appdata. docker run --mount source=appdata,target=/data myimage correctly mounts the named volume appdata. The other options (-v /data appdata and --volume /data:appdata) have invalid syntax or incorrect source/target order.

3. Final Answer:

   docker run --mount source=appdata,target=/data myimage -> Option A

4. Quick Check:

   Use --mount source=appdata,target=/data = B [OK]

Hint: Use --mount source=vol,target=path for clarity [OK]

Common Mistakes:

• Mixing volume and container paths order
• Using incorrect flags like --volume with wrong syntax
• Confusing shorthand and long form options