CHROOT(8) Maintenance Commands and Procedures CHROOT(8)
chroot - change root directory for a command
chroot newroot command
The chroot utility causes command to be executed relative to newroot.
The meaning of any initial slash (/) in the path names is changed to
newroot for command and any of its child processes. Upon execution,
the initial working directory is newroot.
Notice that redirecting the output of command to a file, such as in:
chroot newroot command > xyz
will create the file xyz relative to the original root of command, not
the new one.
The new root path name is always relative to the current root. Even if
a chroot is currently in effect, the newroot argument is relative to
the current root of the running process.
This command can be run only by the super-user.
The exit status of chroot is the exit status of command.
The following operands are supported:
newroot The new root directory.
command The command to be executed relative to newroot.
Example 1 Using the chroot Utility
The chroot utility provides an easy way to extract tar files (see
tar(1)) written with absolute filenames to a different location. It is
necessary to copy the shared libraries used by tar (see ldd(1)) to the
newroot filesystem.
example# mkdir -p /tmp/lib /tmp/usr/lib
example# cd /lib && cp ld.so.1 \
libavl.so.1 libc.so.1 libcmdutils.so.1 libcustr.so.1 \
libm.so.2 libmd.so.1 libmp.so.2 libnsl.so.1 \
libnvpair.so.1 libsec.so.1 libsecdb.so.1 libtsol.so.2 \
libuutil.so.1 /tmp/lib/
example# cp /usr/lib/libidmap.so.1 /tmp/usr/lib/
example# cp /usr/bin/tar /tmp
example# dd if=/dev/rmt/0 | chroot /tmp tar xvf -
cd(1), ldd(1), tar(1), chroot(2), ttyname(3C), attributes(7)
Exercise extreme caution when referencing device files in the new root
file system.
References by routines such as ttyname(3C) to stdin, stdout, and stderr
will find that the device associated with the file descriptor is
unknown after chroot is run.
illumos March 18, 2021 illumos
NAME
chroot - change root directory for a command
SYNOPSIS
chroot newroot command
DESCRIPTION
The chroot utility causes command to be executed relative to newroot.
The meaning of any initial slash (/) in the path names is changed to
newroot for command and any of its child processes. Upon execution,
the initial working directory is newroot.
Notice that redirecting the output of command to a file, such as in:
chroot newroot command > xyz
will create the file xyz relative to the original root of command, not
the new one.
The new root path name is always relative to the current root. Even if
a chroot is currently in effect, the newroot argument is relative to
the current root of the running process.
This command can be run only by the super-user.
EXIT STATUS
The exit status of chroot is the exit status of command.
OPERANDS
The following operands are supported:
newroot The new root directory.
command The command to be executed relative to newroot.
EXAMPLES
Example 1 Using the chroot Utility
The chroot utility provides an easy way to extract tar files (see
tar(1)) written with absolute filenames to a different location. It is
necessary to copy the shared libraries used by tar (see ldd(1)) to the
newroot filesystem.
example# mkdir -p /tmp/lib /tmp/usr/lib
example# cd /lib && cp ld.so.1 \
libavl.so.1 libc.so.1 libcmdutils.so.1 libcustr.so.1 \
libm.so.2 libmd.so.1 libmp.so.2 libnsl.so.1 \
libnvpair.so.1 libsec.so.1 libsecdb.so.1 libtsol.so.2 \
libuutil.so.1 /tmp/lib/
example# cp /usr/lib/libidmap.so.1 /tmp/usr/lib/
example# cp /usr/bin/tar /tmp
example# dd if=/dev/rmt/0 | chroot /tmp tar xvf -
SEE ALSO
cd(1), ldd(1), tar(1), chroot(2), ttyname(3C), attributes(7)
NOTES
Exercise extreme caution when referencing device files in the new root
file system.
References by routines such as ttyname(3C) to stdin, stdout, and stderr
will find that the device associated with the file descriptor is
unknown after chroot is run.
illumos March 18, 2021 illumos