CHROOT(8) Maintenance Commands and Procedures CHROOT(8)
NAME
chroot - change root directory for a command
SYNOPSIS
chroot newroot commandDESCRIPTION
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