post image January 14, 2022 | 1 min Read

Linux Namespaces

Namespaces isolates processess

  • restricts what processes can see.
  • PID namespace:

    • isolates processess from each other
    • one process cannot see others
    • process ID 10 can exist multiple times, once in every namespace
  • Mount namespace:

    • resticts access to filesystem
  • Network namespace:

    • separates network traffic
  • User namespace:

    • user 0 can exist in every namespace and all of them are different


  • resticts the resource usage of processes (RAM, disk, CPU)

Difference between user and kernel space in Linux

Container tools

Take a look at some container tools:

Check how process in containers can be islolated from each other.

docker run --name c1 -d ubuntu sh -c 'sleep 1d'
docker run --name c2 -d ubuntu sh -c 'sleep 999d'
docker exec c1 ps aux
docker exec c2 ps aux

docker rm c2 --force

# now c2 can see processes from container c1
docker run --name c2 --pid=container:c1 -d ubuntu sh -c 'sleep 999d'
docker exec c2 ps aux

author image

Jan Toth

I have been in DevOps related jobs for past 6 years dealing mainly with Kubernetes in AWS and on-premise as well. I spent quite a lot …

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