The main difference between Docker and traditional virtualization lies in the processing and resource usage of the operating system layer. 1. Docker containers share the host OS kernel, which is lighter, faster startup, and more resource efficiency; 2. Each instance of a traditional VM runs a full OS, occupying more space and resources; 3. The container usually starts in a few seconds, and the VM may take several minutes; 4. The container depends on namespace and cgroups to achieve isolation, while the VM obtains stronger isolation through hypervisor simulation hardware; 5. Docker has better portability, ensuring that applications run consistently in different environments, suitable for microservices and cloud environment deployment.

To back up and restore Docker volumes, you need to use temporary containers in conjunction with tar tools. 1. During backup, run a temporary container that mounts the target volume, use the tar command to package the data and save it to the host; 2. During recovery, copy the backup file to the container that mounts the volume and decompress it, pay attention to path matching and possible overwriting of data; 3. Multiple volumes can be written to automatically cycle through each volume; 4. It is recommended to operate when the container is stopped to ensure data consistency, and regularly test the recovery process to verify the backup validity.

To expose Docker container ports, the host needs to access the container service through port mapping. 1. Use the dockerrun-p[host_port]:[container_port] command to run the container, such as dockerrun-p8080:3000my-web-app; 2. Use the EXPOSE instruction to mark the purpose in the Dockerfile, such as EXPOSE3000, but the port will not be automatically published; 3. Configure the ports segment of the yml file in DockerCompose, such as ports:-"8080:3000"; 4. Use dockerps to check whether the port map is generated after running.

To view the metadata of the Docker image, the dockerinspect command is mainly used. 1. Execute dockerinspect to obtain complete metadata information, including ID, architecture, layer summary and configuration details; 2. Use Go templates to format the output, such as dockerinspect--format='{{.Os}}/{{.Architecture}}' to display only the operating system and architecture; 3. Use dockerhistory to view each layer of information during the image construction process to help optimize the image structure; 4. Use skopeo tool skopeoinspectdocker:///: to obtain without pulling the complete image.

Docker has three main volume types: namedvolumes, bindmounts, and tmpfsmounts. namedvolumes are managed by Docker and are suitable for scenarios where persistent data is required, such as databases; bindmounts map host-specific paths to containers, suitable for sharing code or configuration during development; tmpfsmounts stores data in memory, suitable for temporary or sensitive information. When using it, select the appropriate type according to your needs to optimize container data management.

To access services in Docker container from the host, use port mapping. The specific steps are: 1. Use -p to specify host_port:container_port when starting the container, such as dockerrun-d-p8080:80nginx; 2. Multiple ports can be configured through multiple -p parameters or DockerCompose files; 3. IP address binding can be limited, such as -p192.168.1.100:8080:80; 4. Use dockerps or dockerinspect to view port mapping details.

Using lightweight basic images, merging and optimizing RUN instructions, and copying only necessary files are the key to reducing Docker images size. 1. Select lightweight basic images such as alpine, distroless or scratch to reduce unnecessary system components; 2. Merge multiple RUN commands and clean caches in time, such as combining apt-getupdate with installation commands, and delete /var/lib/apt/lists/*; 3. Exclude non-essential files through .dockerignore, use multi-stage construction to separate compilation and runtime dependencies, and copy only the necessary configuration and executable files into the final image. These methods can effectively reduce mirror size, improve construction and deployment efficiency, and reduce security

WhenchoosingbetweennamedvolumesandbindmountsinDocker,usenamedvolumesforcross-hostconsistency,reliabledatapersistence,andDocker-managedstorage,especiallyinproductionenvironments.①Namedvolumesautomaticallyhandlestoragepaths,ensuringportabilityacrossdev