php man page for switch_root

SWITCH_ROOT(8)						       System Administration						    SWITCH_ROOT(8)

NAME
       switch_root - switch to another filesystem as the root of the mount tree

SYNOPSIS
       switch_root [-hV]

       switch_root newroot init [arg...]

DESCRIPTION
       switch_root moves already mounted /proc, /dev, /sys and /run to newroot and makes newroot the new root filesystem and starts init process.

       WARNING: switch_root removes recursively all files and directories on the current root filesystem.

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

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

RETURN VALUE
       switch_root returns 0 on success and 1 on failure.

NOTES
       switch_root  will  fail	to  function if newroot is not the root of a mount. If you want to switch root into a directory that does not meet
       this requirement then you can first use a bind-mounting trick to turn any directory into a mount point:

	      mount --bind $DIR $DIR

SEE ALSO
       chroot(2), init(8), mkinitrd(8), mount(8)

AUTHORS
       Peter Jones <pjones@redhat.com>
       Jeremy Katz <katzj@redhat.com>
       Karel Zak <kzak@redhat.com>

AVAILABILITY
       The switch_root command is part of the util-linux package and is available from https://www.kernel.org/pub/linux/utils/util-linux/.

util-linux							     June 2009							    SWITCH_ROOT(8)