freebsd-dev/sbin/fsck_ffs/SMM.doc/1.t
Adrian Chadd 9ea6f4f0be Reviewed by: rwatson, bp
Approved by:	rwatson
Obtained from:	NetBSD-current source tree

The beginnings of the fsck wrappers stuff from NetBSD. This particular commit
brings a newly repo-copied sbin/fsck_ffs/ (from sbin/fsck/) into fsck wrappers
mode.

A quick overview (the code reflects this):

* Documentation changed to reflect fsck_ffs instead of fsck
* Simply acts on a single filesystem, doesn't try to do any multiple filesystem
  magic - this is done by the fsck wrappers now

And then specific to fsck_ffs:

* link to /sbin/fsck_4.2bsd and /sbin/fsck_ufs. This is because right now
  the filesystem is of type ufs not ffs, and that during autodetection the
  labeltype rather than the VFS type is used - this is because when doing
  an autodetection of filesystem type in the fsck wrapper program, it does
  not have any link between label type (4.2bsd, vinum, etc) and VFS string.

Note that this shouldn't break a build since the required buildworld Makefile
magic and import of the fsck wrapper code into src/sbin/fsck/ will happen
in a seperate commit.
2000-10-09 08:26:35 +00:00

85 lines
3.3 KiB
Perl

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.\" @(#)1.t 8.1 (Berkeley) 6/5/93
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.ds RH Introduction
.NH
Introduction
.PP
This document reflects the use of
.I fsck_ffs
with the 4.2BSD and 4.3BSD file system organization. This
is a revision of the
original paper written by
T. J. Kowalski.
.PP
When a UNIX
operating system is brought up, a consistency
check of the file systems should always be performed.
This precautionary measure helps to insure
a reliable environment for file storage on disk.
If an inconsistency is discovered,
corrective action must be taken.
.I Fsck_ffs
runs in two modes.
Normally it is run non-interactively by the system after
a normal boot.
When running in this mode,
it will only make changes to the file system that are known
to always be correct.
If an unexpected inconsistency is found
.I fsck_ffs
will exit with a non-zero exit status,
leaving the system running single-user.
Typically the operator then runs
.I fsck_ffs
interactively.
When running in this mode,
each problem is listed followed by a suggested corrective action.
The operator must decide whether or not the suggested correction
should be made.
.PP
The purpose of this memo is to dispel the
mystique surrounding
file system inconsistencies.
It first describes the updating of the file system
(the calm before the storm) and
then describes file system corruption (the storm).
Finally,
the set of deterministic corrective actions
used by
.I fsck_ffs
(the Coast Guard
to the rescue) is presented.
.ds RH Overview of the File System