NAME

       ipc_namespaces - overview of Linux IPC namespaces

DESCRIPTION

       IPC  namespaces  isolate  certain  IPC  resources,  namely,  System  V  IPC  objects  (see
       sysvipc(7)) and (since Linux 2.6.30)  POSIX  message  queues  (see  mq_overview(7)).   The
       common  characteristic  of  these  IPC  mechanisms  is  that IPC objects are identified by
       mechanisms other than filesystem pathnames.

       Each IPC namespace has its own set of System V IPC identifiers and its own  POSIX  message
       queue  filesystem.  Objects created in an IPC namespace are visible to all other processes
       that are members of that namespace,  but  are  not  visible  to  processes  in  other  IPC
       namespaces.

       The following /proc interfaces are distinct in each IPC namespace:

       •  The POSIX message queue interfaces in /proc/sys/fs/mqueue.

       •  The  System  V IPC interfaces in /proc/sys/kernel, namely: msgmax, msgmnb, msgmni, sem,
          shmall, shmmax, shmmni, and shm_rmid_forced.

       •  The System V IPC interfaces in /proc/sysvipc.

       When an IPC namespace is destroyed (i.e., when the last process that is a  member  of  the
       namespace terminates), all IPC objects in the namespace are automatically destroyed.

       Use of IPC namespaces requires a kernel that is configured with the CONFIG_IPC_NS option.

SEE ALSO

       nsenter(1),  unshare(1),  clone(2),  setns(2),  unshare(2), mq_overview(7), namespaces(7),
       sysvipc(7)