pivot_root(8) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | EXAMPLE | SEE ALSO | REPORTING BUGS | AVAILABILITY

PIVOT_ROOT(8)             System Administration            PIVOT_ROOT(8)

NAME         top

       pivot_root - change the root filesystem

SYNOPSIS         top

       pivot_root new_root put_old

DESCRIPTION         top

       pivot_root moves the root file system of the current process to
       the directory put_old and makes new_root the new root file
       system. Since pivot_root(8) simply calls pivot_root(2), we refer
       to the man page of the latter for further details.

       Note that, depending on the implementation of pivot_root, root
       and current working directory of the caller may or may not
       change. The following is a sequence for invoking pivot_root that
       works in either case, assuming that pivot_root and chroot are in
       the current PATH:

           cd new_root
           pivot_root . put_old
           exec chroot . command

       Note that chroot must be available under the old root and under
       the new root, because pivot_root may or may not have implicitly
       changed the root directory of the shell.

       Note that exec chroot changes the running executable, which is
       necessary if the old root directory should be unmounted
       afterwards. Also note that standard input, output, and error may
       still point to a device on the old root file system, keeping it
       busy. They can easily be changed when invoking chroot (see below;
       note the absence of leading slashes to make it work whether
       pivot_root has changed the shell’s root or not).

OPTIONS         top

       -V, --version
           Display version information and exit.

       -h, --help
           Display help text and exit.

EXAMPLE         top

       Change the root file system to /dev/hda1 from an interactive
       shell:

           mount /dev/hda1 /new-root
           cd /new-root
           pivot_root . old-root
           exec chroot . sh <dev/console >dev/console 2>&1
           umount /old-root

       Mount the new root file system over NFS from 10.0.0.1:/my_root
       and run init:

           ifconfig lo 127.0.0.1 up   # for portmap
           # configure Ethernet or such
           portmap   # for lockd (implicitly started by mount)
           mount -o ro 10.0.0.1:/my_root /mnt
           killall portmap   # portmap keeps old root busy
           cd /mnt
           pivot_root . old_root
           exec chroot . sh -c 'umount /old_root; exec /sbin/init' \
             <dev/console >dev/console 2>&1

SEE ALSO         top

       chroot(1), pivot_root(2), mount(8), switch_root(8), umount(8)

REPORTING BUGS         top

       For bug reports, use the issue tracker at
       https://github.com/karelzak/util-linux/issues.

AVAILABILITY         top

       The pivot_root command is part of the util-linux package which
       can be downloaded from Linux Kernel Archive
       <https://www.kernel.org/pub/linux/utils/util-linux/>. This page
       is part of the util-linux (a random collection of Linux
       utilities) project. Information about the project can be found at
       ⟨https://www.kernel.org/pub/linux/utils/util-linux/⟩. If you have
       a bug report for this manual page, send it to
       util-linux@vger.kernel.org. This page was obtained from the
       project's upstream Git repository
       ⟨git://git.kernel.org/pub/scm/utils/util-linux/util-linux.git⟩ on
       2021-08-27. (At that time, the date of the most recent commit
       that was found in the repository was 2021-08-24.) If you discover
       any rendering problems in this HTML version 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 manual page),
       send a mail to man-pages@man7.org

util-linux 2.37.85-637cc       2021-04-02                  PIVOT_ROOT(8)

Pages that refer to this page: pivot_root(2)initrd(4)lxc.container.conf(5)mount_namespaces(7)pivot_root(8)