Namespaces in operation, part 4: more on PID namespaces

Namespaces in operation, part 4: more on PID namespaces

As described in the article, the setns() and unshare() system calls treat PID namespaces specially. For other types of namespaces, these system calls do change the namespace of the caller. For PID namespaces, these system calls do not change the PID namespace of the calling process. Instead, any subsequently created children of the caller will be created in the target/new namespace.

If the -f option was omitted, the ns_run command would execute the orphan program in the PID namespace where ns_run resides, rather than the namespace specified by the -n option.

Note: you can avoid this step in the future by logging into your LWN account.