namespaces(7) Miscellaneous Information Manual namespaces(7) namespaces - . . . /proc . . . . . ------------------------------------------------------------------------------------------------------------------------------ CLONE_NEWCGROUP cgroup_namespaces(7) IPC CLONE_NEWIPC ipc_namespaces(7) IPC System V POSIX CLONE_NEWNET network_namespaces(7) CLONE_NEWNS mount_namespaces(7) PID CLONE_NEWPID pid_namespaces(7) CLONE_NEWTIME time_namespaces(7) CLONE_NEWUSER user_namespaces(7) UTS CLONE_NEWUTS uts_namespaces(7) NIS /proc : clone(2) clone(2) . flags CLONE_NEW* . ( .) setns(2) setns(2) . /proc/pid/ns . unshare(2) unshare(2) . flags CLONE_NEW* . ( .) ioctl(2) ioctl(2) . ioctl_nsfs(2). clone(2) unshare(2) CAP_SYS_ADMIN . : Linux 3.8 . /proc/pid/ns/ /proc/pid/ns/ setns(2): $ ls -l /proc/$$/ns | awk '{print $1, $9, $10, $11}' total 0 lrwxrwxrwx. cgroup -> cgroup:[4026531835] lrwxrwxrwx. ipc -> ipc:[4026531839] lrwxrwxrwx. mnt -> mnt:[4026531840] lrwxrwxrwx. net -> net:[4026531969] lrwxrwxrwx. pid -> pid:[4026531836] lrwxrwxrwx. pid_for_children -> pid:[4026531834] lrwxrwxrwx. time -> time:[4026531834] lrwxrwxrwx. time_for_children -> time:[4026531834] lrwxrwxrwx. user -> user:[4026531837] lrwxrwxrwx. uts -> uts:[4026531838] ( mount(2)) pid . ( ) pid. . setns(2). 3.7 . 3.8 . /proc/pid/ns/xxx stat.st_dev stat.st_ino stat(2). : $ readlink /proc/$$/ns/uts uts:[4026531838] : /proc/pid/ns/cgroup ( 4.6) cgroup . /proc/pid/ns/ipc ( 3.0) IPC . /proc/pid/ns/mnt ( 3.8) . /proc/pid/ns/net ( 3.0) . /proc/pid/ns/pid ( 3.8) PID . ( PID ). /proc/pid/ns/pid_for_children ( 4.12) PID . unshare(2) setns(2) ( pid_namespaces(7)) /proc/pid/ns/pid. . ( readlink(2) .) /proc/pid/ns/time ( 5.6) . /proc/pid/ns/time_for_children ( 5.6) . unshare(2) setns(2) ( time_namespaces(7)) /proc/pid/ns/time. /proc/pid/ns/user ( 3.8) . /proc/pid/ns/uts ( 3.0) UTS . (readlink(2)) ptrace PTRACE_MODE_READ_FSCREDS ptrace(2). /proc/sys/user /proc/sys/user ( 4.9) . : max_cgroup_namespaces cgroup . max_ipc_namespaces ipc . max_mnt_namespaces . max_net_namespaces . max_pid_namespaces PID . max_time_namespaces ( 5.7) . max_user_namespaces . max_uts_namespaces uts . : o . o . o . . o UID 0. o ( PID ) . o clone(2) unshare(2) ENOSPC. o (/proc/sys/kernel/threads-max). MAXINT. o . : o . o . o . . . : o /proc/pid/ns/* . o ( PID ) . o . o PID /proc/pid/ns/pid_for_children. o /proc/pid/ns/time_for_children. o IPC mqueue ( mq_overview(7)) . o PID proc(5) . clone(2) user_namespaces(7). nsenter(1), readlink(1), unshare(1), clone(2), ioctl_nsfs(2), setns(2), unshare(2), proc(5), capabilities(7), cgroup_namespaces(7), cgroups(7), credentials(7), ipc_namespaces(7), network_namespaces(7), pid_namespaces(7), user_namespaces(7), uts_namespaces(7), lsns(8), switch_root(8) 3 . . : . 6.18 8 2026 namespaces(7)