Virtualization & Container Management Flashcards

Which command migrates a running KVM virtual machine to another host without downtime?

Answer: virsh migrate --live

'virsh migrate --live' performs live migration, transferring VM memory pages to the target host while the guest continues running.

What is the difference between a Docker image and a Docker container?

Answer: Images are read-only templates; containers are writable running instances

A Docker image is an immutable layered template, while a container is a live, writable instance created from that image.

What does 'virt-clone' do in a KVM environment?

Answer: Creates a copy of an existing virtual machine definition and disk

virt-clone duplicates an existing VM's XML configuration and disk image to create a new independent virtual machine.

Which Docker networking mode shares the host's network stack directly with the container?

Answer: host

In 'host' network mode, the container uses the host's network interfaces directly with no isolation or NAT.

What does the OCI (Open Container Initiative) standardize?

Answer: Container image format and runtime specifications

OCI defines open industry standards for container image format (image-spec) and container runtime behavior (runtime-spec).

In a KVM environment, what is SPICE used for?

Answer: Remote display protocol for virtual machine graphical consoles

SPICE (Simple Protocol for Independent Computing Environments) provides high-performance remote display access to KVM VM graphical consoles.

Which flag in 'docker run' automatically removes the container when it exits?

Answer: --rm

The '--rm' flag tells Docker to automatically remove the container's writable layer and metadata when the container stops.