What does docker volume mean?

In docker, the essence of a volume is a file or directory, which exists in one or more containers and is mounted to the container by docker. It does not belong to the joint file system; modifications to the data volume will take effect immediately, and the data Volume updates do not affect the mirror.

The operating environment of this tutorial: linux7.3 system, docker-1.13.1 version, Dell G3 computer.

What docker volumes mean

The essence of a volume is a file or directory, which exists in one or more containers and is mounted to the container by docker, but does not belong to the joint file system. The concept of volumes not only solves the problem of data persistence, but also solves the problem of sharing data between containers.

Why use container volumes

• Data persistence ensures that data is not lost when the container is restarted, for example, we You can use volumes to persist the MySQL directory so that database data will not be lost when the container is restarted.

• If the data is stored in the mirror, it is inconvenient for other processes on the host to access the data.

What are the characteristics of container volumes

• Data volumes can be shared between containers or Reuse data

• Changes in the data volume will not be included in the update of the mirror

• Changes in the volume can take effect directly

• The life cycle of a data volume continues until no container uses it

Creating a data volume

Data volume creation command

docker volume create myvolume

Tips: By default, the data volume created by Docker is in local mode and can only provide container access to this host.

Use -v command

docker run -it -v 宿主机绝对路径目录:容器内目录 镜像名

Tips: Use -v to specify the path that needs to be persisted in the container. Docker will automatically create a volume for us and bind it to the container.

Test:

docker run -it -v /home/ceshi:/home centos /bin/bash

Check whether the data volume is mounted successfully:

docker inspect 容器id

Recommended study: "docker video tutorial"

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