The
/rescue
directory contains a collection of common utilities intended for use
in recovering a badly damaged system.
With the transition to a dynamically-linked root beginning with
Fx 5.2 ,
there is a real possibility that the standard tools in
/bin
and
/sbin
may become non-functional due to a failed upgrade or a disk error.
The tools in
/rescue
are statically linked and should therefore be more resistant to
damage.
However, being statically linked, the tools in
/rescue
are also less functional than the standard utilities.
In particular, they do not have full use of the locale,
pam(3),
and nsswitch libraries.
If your system fails to boot, and it shows a prompt similar to:
"Enter full pathname of shell or RETURN for /bin/sh:
the first thing to try running is the standard shell,
/bin/sh
If that fails, try running
/rescue/sh
which is the
shell.
To repair the system, the root partition must first be remounted
read-write.
This can be done with the following
mount(8)
command:
"/rescue/mount -uw /"
The next step is to double-check the contents of
/bin , /sbin
and
/usr/lib
possibly mounting a
Fx rescue or
``live file system''
CD-ROM (e.g.,
disc2
of the officially released
Fx ISO images) and copying files from there.
Once it is possible to successfully run
/bin/sh , /bin/ls
and other standard utilities, try rebooting back into the standard
system.
The
/rescue
tools are compiled using
crunchgen(1),
which makes them considerably more compact than the standard
utilities.
To build a
Fx system where space is critical,
/rescue
can be used as a replacement for the standard
/bin
and
/sbin
directories; simply change
/bin
and
/sbin
to be symbolic links pointing to
/rescue
Since
/rescue
is statically linked, it should also be possible to dispense with much
of
/usr/lib
in such an environment.
In contrast to its predecessor
/stand
/rescue
is updated during normal
Fx source and binary upgrades.
An -nosplit
The
system was written by
An Tim Kientzle Aq kientzle@FreeBSD.org ,
based on ideas taken from
Nx .
This manual page was written by
An Simon L. Nielsen Aq simon@FreeBSD.org ,
based on text by
An Tim Kientzle Aq kientzle@FreeBSD.org .
BUGS
Most of the
tools work even in a fairly crippled system.
The most egregious exception is the
version of
vi(1),
which currently requires that
/usr
be mounted so that it can access the
termcap(5)
files.
Hopefully, a failsafe
termcap(3)
entry will eventually be added into the
ncurses(3)
library, so that
/rescue/vi
can be used even in a system where
/usr
cannot immediately be mounted.
In the meantime, the
version of the
ed(1)
editor can be used from
/rescue/ed
if you need to edit files, but cannot mount
/usr
