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RESCUE(8) FreeBSD System Manager's Manual RESCUE(8)
NAME
rescue - rescue utilities in /rescue
DESCRIPTION
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 FreeBSD 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 rescue 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 FreeBSD rescue or "live file system" CD-ROM
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
FreeBSD 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
FreeBSD source and binary upgrades.
FILES
/rescue Root of the rescue hierarchy.
SEE ALSO
crunchgen(1), crash(8)
HISTORY
The rescue utilities first appeared in FreeBSD 5.2.
AUTHORS
The rescue system was written by Tim Kientzle <kientzle@FreeBSD.org>,
based on ideas taken from NetBSD. This manual page was written by Simon
L. Nielsen <simon@FreeBSD.org>, based on text by Tim Kientzle
<kientzle@FreeBSD.org>.
of the ed(1) editor can be used from /rescue/ed if you need to edit
files, but cannot mount /usr.
FreeBSD 14.2-RELEASE June 30, 2022 FreeBSD 14.2-RELEASE