In Docker's architecture, which two Linux concepts are the fundamental building blocks?

In Docker's architecture, which two Linux concepts are the fundamental building blocks?

• A. cgroups and namespaces
• B. chroot and virtualization
• C. LXC and tooling
• D. Linux Namespaces and cgroups

Answer: (D)

The essential building blocks Docker relies on are Linux Namespaces and cgroups. Namespaces provide process isolation—different namespaces give each container its own separate PID space, mount points, network stack, IPC, and hostname—so processes inside a container don’t see the host or other containers. Cgroups (control groups) manage and limit the resources those processes can use, such as CPU, memory, and I/O, ensuring fair sharing and accountability. Together, these kernel features enable OS-level virtualization: multiple isolated containers share the same kernel but run with separate environments and controlled resources. The precise phrasing Linux Namespaces and cgroups points to the canonical kernel features Docker leverages, making it the best match. The other options reference related ideas (chroot, virtualization; LXC and tooling) but don’t capture the same fundamental kernel building blocks that Docker is built upon.

The essential building blocks Docker relies on are Linux Namespaces and cgroups. Namespaces provide process isolation—different namespaces give each container its own separate PID space, mount points, network stack, IPC, and hostname—so processes inside a container don’t see the host or other containers. Cgroups (control groups) manage and limit the resources those processes can use, such as CPU, memory, and I/O, ensuring fair sharing and accountability. Together, these kernel features enable OS-level virtualization: multiple isolated containers share the same kernel but run with separate environments and controlled resources.

The precise phrasing Linux Namespaces and cgroups points to the canonical kernel features Docker leverages, making it the best match. The other options reference related ideas (chroot, virtualization; LXC and tooling) but don’t capture the same fundamental kernel building blocks that Docker is built upon.