Problem Statement
What is OS-level virtualisation and what are its advantages and limitations?
Explanation
OS-level virtualisation is the technique where multiple isolated user-space instances (containers or zones) run on a single operating system kernel, sharing that kernel and underlying hardware. For example, technologies like Solaris Zones or OpenVZ implement OS-level virtualisation. Advantages include lightweight operation, near-native performance, fast startup, efficient resource use. Limitations include less isolation compared to full virtual machines (since kernel is shared), and inability to run different OS kernels or completely different operating systems. Demonstrating both sides (advantages and limitations) is key for interview depth.
