305-300 Exam Dumps : LPIC-3: Virtualization and Containerization - Exam 305, version 3.0

The command that deletes all volumes which are not associated with a container is docker volume prune. This command removes all unused local volumes, which are those that are not referenced by any containers. By default, it only removes anonymous volumes, which are those that are not given a specific name when they are created. To remove both unused anonymous and named volumes, the --all or -a flag can be added to the command. The command will prompt for confirmation before deleting the volumes, unless the --force or -f flag is used to bypass the prompt. The command will also show the total reclaimed space after deleting the volumes12.

The other commands listed in the question are not valid or do not have the same functionality as docker volume prune. They are either made up, misspelled, or have a different purpose. These commands are:

docker volume cleanup: This command does not exist in Docker. There is no cleanup subcommand for docker volume.

docker volume orphan -d: This command does not exist in Docker. There is no orphan subcommand for docker volume, and the -d flag is not a valid option for any docker volume command.

docker volume vacuum: This command does not exist in Docker. There is no vacuum subcommand for docker volume.

docker volume garbage-collect: This command does not exist in Docker. There is no garbage-collect subcommand for docker volume.

References:

docker volume prune | Docker Docs

How to Remove all Docker Volumes - YallaLabs.

The purpose of a .dockerignore file is to specify files that Docker does not submit to the Docker daemon when building a Docker image. A .dockerignore file is a text file that contains a list of files or directories that should be excluded from the build context, which is the set of files and folders that are available for use in a Dockerfile. By using a .dockerignore file, you can avoid sending files or directories that are large, contain sensitive information, or are irrelevant to the Docker image to the daemon, which can improve the efficiency and security of the build process. The other options are incorrect because they do not describe the function of a .dockerignore file. Option A is wrong because a .dockerignore file does not affect the files existing in a Docker image, but only the files sent to the daemon during the build. Option C is wrong because a .dockerignore file does not exist in the root file system of containers, but in the same directory as the Dockerfile. Option D is wrong because a .dockerignore file does not affect the volumes that Docker attaches to a container, but only the files included in the build context. Option E is wrong because a .dockerignore file does not affect the parts of a Dockerfile that are executed, but only the files available for use in a Dockerfile. References:

What are .dockerignore files, and why you should use them?

Dockerfile reference | Docker Docs

How to use .dockerignore and its importance - Shisho Cloud

The correct command to boot a QEMU virtual machine using hardware virtualization extensions is qemu -accel kvm -drive file-debian.img -cdrom debian.iso -m 1024 -boot d. This command uses the -accel option to specify the hardware accelerator to use, which in this case is kvm. KVM is a full virtualization solution for Linux on x86 hardware containing virtualization extensions (Intel VT or AMD-V)1. The -drive option specifies the disk image file to use, which in this case is debian.img. The -cdrom option specifies the ISO image file to use as a CD-ROM, which in this case is debian.iso. The -m option specifies the amount of memory to allocate to the virtualmachine, which in this case is 1024 MB. The -boot option specifies the boot order, which in this case is d, meaning to boot from the CD-ROM first. References: