LXC-UNSHARE(1)                                                LXC-UNSHARE(1)

NAME         top

       lxc-unshare - Run a task in a new set of namespaces.

SYNOPSIS         top

       lxc-unshare -s namespaces [ -u user ]  [ -H hostname ]  [ -i ifname ]
       [ -d ]  [ -M ]  command

DESCRIPTION         top

       lxc-unshare can be used to run a task in a cloned set of namespaces.
       This command is mainly provided for testing purposes.  Despite its
       name, it always uses clone rather than unshare to create the new task
       with fresh namespaces. Apart from testing kernel regressions this
       should make no difference.

OPTIONS         top

       -s namespaces
              Specify the namespaces to attach to, as a pipe-separated list,
              e.g. NETWORK|IPC. Allowed values are MOUNT, PID, UTSNAME, IPC,
              USER  and NETWORK. This allows one to change the context of
              the process to e.g. the network namespace of the container
              while retaining the other namespaces as those of the host.
              (The pipe symbol needs to be escaped, e.g.  MOUNT\|PID or
              quoted, e.g.  "MOUNT|PID".)

       -u user
              Specify a userid which the new task should become.

       -H hostname
              Set the hostname in the new container. Only allowed if the
              UTSNAME namespace is set.

       -i interfacename
              Move the named interface into the container. Only allowed if
              the NETWORK namespace is set. You may specify this argument
              multiple times to move multiple interfaces into container.

       -d     Daemonize (do not wait for the container to exit before

       -M     Mount default filesystems (/proc /dev/shm and /dev/mqueue) in
              the container. Only allowed if MOUNT namespace is set.

EXAMPLES         top

       To spawn a new shell with its own UTS (hostname) namespace,

                 lxc-unshare -s UTSNAME /bin/bash

       If the hostname is changed in that shell, the change will not be
       reflected on the host.

       To spawn a shell in a new network, pid, and mount namespace,

                 lxc-unshare -s "NETWORK|PID|MOUNT" /bin/bash

       The resulting shell will have pid 1 and will see no network
       interfaces.  After re-mounting /proc in that shell,

                 mount -t proc proc /proc

       ps output will show there are no other processes in the namespace.

       To spawn a shell in a new network, pid, mount, and hostname

                 lxc-unshare -s "NETWORK|PID|MOUNT|UTSNAME" -M -H slave -i veth1 /bin/bash

       The resulting shell will have pid 1 and will see two network
       interfaces (lo and veth1). The hostname will be "slave" and /proc
       will have been remounted. ps output will show there are no other
       processes in the namespace.

SEE ALSO         top

       lxc(7), lxc-create(1), lxc-copy(1), lxc-destroy(1), lxc-start(1),
       lxc-stop(1), lxc-execute(1), lxc-console(1), lxc-monitor(1),
       lxc-wait(1), lxc-cgroup(1), lxc-ls(1), lxc-info(1), lxc-freeze(1),
       lxc-unfreeze(1), lxc-attach(1), lxc.conf(5)

AUTHOR         top

       Daniel Lezcano <>

COLOPHON         top

       This page is part of the lxc (Linux containers) project.  Information
       about the project can be found at ⟨⟩.  If
       you have a bug report for this manual page, send it to  This page was obtained from the
       project's upstream Git repository ⟨git://⟩ on
       2017-03-13.  If you discover any rendering problems in this HTML ver‐
       sion of the page, or you believe there is a better or more up-to-date
       source for the page, or you have corrections or improvements to the
       information in this COLOPHON (which is not part of the original man‐
       ual page), send a mail to

                                 2017-03-13                   LXC-UNSHARE(1)