Which component is commonly used to isolate Docker on non-Linux hosts?

Which component is commonly used to isolate Docker on non-Linux hosts?

• A. A dedicated kernel patch
• B. A virtual machine or subsystem
• C. A hidden virtual machine or "subsystem"
• D. A network router

Answer: (C)

Containers rely on Linux kernel features like namespaces and cgroups, which aren’t natively exposed on non-Linux hosts. To provide those capabilities, Docker runs inside a hidden virtual machine or subsystem that hosts a Linux environment behind the scenes. This isolation ensures the container runtime has a proper Linux kernel and userland to operate, regardless of whether the host is macOS or Windows. Using a VM or subsystem is the practical way to provide the necessary isolation; patching the host kernel would require changing the host itself, which isn’t how Docker works on non-Linux systems. A network router isn’t involved in isolating Docker containers.

Containers rely on Linux kernel features like namespaces and cgroups, which aren’t natively exposed on non-Linux hosts. To provide those capabilities, Docker runs inside a hidden virtual machine or subsystem that hosts a Linux environment behind the scenes. This isolation ensures the container runtime has a proper Linux kernel and userland to operate, regardless of whether the host is macOS or Windows. Using a VM or subsystem is the practical way to provide the necessary isolation; patching the host kernel would require changing the host itself, which isn’t how Docker works on non-Linux systems. A network router isn’t involved in isolating Docker containers.