logo

What are Linux Namespaces

Last Updated: 2024-07-23

A namespace wraps a global system resource in an abstraction that makes it appear to the processes within the namespace that they have their own isolated instance of the global resource.

There are 7 namespaces in Linux:

  • Cgroup: cgroup = control group. Resource limiting, prioritization, accounting and control.
  • IPC: Inter-process Communication.
  • Network: Network devices, ports, etc.
  • Mount: Mount points (of file systems).
  • PID: Process IDs.
  • User: User and group IDs.
  • UTS: UNIX Timesharing System, named after the data structure used to store info returned by uname system call. Isolates hostname and NIS domain name.

cgroup

Read more: cgroup

Networking

Each network namespace has its own localhost and loopback (lo) device. If loopback device is not up, localhost would not work.