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Updated on 2025-03-10

In-depth understanding of Docker Data Volume

A deep understanding of Docker Data Volume

In the application scenario of Docker containers,Data persistenceIt is essential. This article will explore in-depth the core component of Docker - Data Volume, to help everyone understand how to effectively manage data in containers.

1. What is a Docker data volume

Docker data volumes are a data persistence method provided by Docker, which enables data to be shared between containers and can be saved for a long time. Even if the container is deleted, the data in the volume still exists. Its core functions include:

  • Persistent storage of data
  • Data sharing among multiple containers
  • Quick recovery of data during container restart or migration

2. Docker data volume command

passdocker volumeThe commands can easily create, manage, view and delete data volumes. The specific instructions are as follows:

1. Command prefix format

docker volume [commands]

This command determines the operation performed based on subsequent parameters. The main commands are as follows:

  • create: Create a data volume
  • inspect: Display information about the data volume
  • ls: List all data volumes
  • prune: Delete unused data volumes
  • rm: Delete one or more data volumes

2. Common operation examples

(1) Create a data volume

We can usedocker volume create [volume_name]Command to create a data volume. for example:

docker volume create html

(2) View the data volume

All data volumes can be viewed through the following command:

docker volume ls

To view the information of the specified data volume, you can use:

docker volume inspect html

(3) Delete the data volume

If the data volume is no longer needed, you can delete it using the following command:

docker volume rm html

3. Mounting and use of data volumes

The core value of a data volume is that it can be used in combination with containers. Specifically, it is divided into two methods: mounting a data volume and mounting a host specified directory:

1. Run the container and mount the data volume

Taking Nginx as an example, use-vParameters mount the data volume into the container:

docker run --name myNginx -v html:/usr/share/nginx/html -p 80:80 -d nginx

in:

-v html:/usr/share/nginx/html: meanshtmlData volumes mounted into container/usr/share/nginx/htmlUnder the path

2. Run the container and mount the host specified directory

In some scenarios, the specified directory on the host can be directly mounted. The following example shows how to mount configuration and data directories on the host into a MySQL container:

docker run \
--name mysql \
-e MYSQL_ROOT_PASSWORD=123456 \
-v /tmp/mysql/conf:/etc/mysql/ \
-v /tmp/mysql/data:/var/lib/mysql \
-p 3306:3306 \
-d mysql

4. The difference between data volume mount and directory mount

In Docker,Data volume mountandDirectory mountThere are two different data management methods, each with its advantages and disadvantages:

Data volume mount：

  • Managed by Docker, it is convenient for data persistence and has good decoupling.
  • The data is deep and the path is in the host/var/lib/docker/volumes, not easy to find.

Directory mount：

  • It is necessary to manually manage the host directory, which is easy to operate and easy to find.
  • The coupling degree between the container and the host is relatively high and the migration is poor.

5. Best practices for data volumes

  • Use data volumes to persist data for containerized applications to avoid data loss with container destruction.
  • For configuration files, using directory mounts can facilitate us to edit configuration files directly on the host. Clean unused data volumes regularly to avoid taking up a lot of disk space.

Conclusion

Data volumes are one of the key mechanisms in Docker for data persistence and sharing. Mastering their usage not only helps the data management of containerized applications, but also provides strong support in application migration, upgrade and other processes.

This is the end of this article about in-depth understanding of Docker Data Volume. For more related Docker data volume content, please search for my previous articles or continue browsing the related articles below. I hope everyone will support me in the future!