1.\" $OpenBSD: badsect.8,v 1.14 2003/09/02 18:30:27 jmc Exp $ 2.\" $NetBSD: badsect.8,v 1.8 1995/03/18 14:54:27 cgd Exp $ 3.\" 4.\" Copyright (c) 1985, 1991, 1993 5.\" The Regents of the University of California. All rights reserved. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 3. Neither the name of the University nor the names of its contributors 16.\" may be used to endorse or promote products derived from this software 17.\" without specific prior written permission. 18.\" 19.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29.\" SUCH DAMAGE. 30.\" 31.\" @(#)badsect.8 8.1 (Berkeley) 6/5/93 32.\" 33.Dd June 5, 1993 34.Dt BADSECT 8 35.Os 36.Sh NAME 37.Nm badsect 38.Nd create files to contain bad sectors 39.Sh SYNOPSIS 40.Nm badsect 41.Ar bbdir sector Op Ar ... 42.Sh DESCRIPTION 43.Nm 44makes a file to contain a bad sector. 45Normally, bad sectors 46are made inaccessible by the standard formatter, which provides 47a forwarding table for bad sectors to the driver; see 48.Xr bad144 8 49for details. 50If a driver supports the bad blocking standard, it is much more preferable 51to use that method to isolate bad blocks, since the bad block forwarding 52makes the pack appear perfect, and such packs can then be copied with 53.Xr dd 1 . 54The technique used by this program is also less general than 55bad block forwarding, as 56.Nm 57can't make amends for 58bad blocks in the i-list of file systems or in swap areas. 59.Pp 60On some disks, 61adding a sector which is suddenly bad to the bad sector table 62currently requires the running of the standard 63.Tn DEC 64formatter. 65Thus to deal with a newly bad block 66or on disks where the drivers 67do not support the bad-blocking standard 68.Nm 69may be used to good effect. 70.Pp 71.Nm 72is used on a quiet file system in the following way: 73First mount the file system, and change to its root directory. 74Make a directory 75.Li BAD 76there. 77Run 78.Nm badsect , 79giving as argument the 80.Ar BAD 81directory followed by 82all the bad sectors you wish to add. 83(The sector numbers must be relative to the beginning of 84the file system, but this is not hard as the system reports 85relative sector numbers in its console error messages.) 86Then change back to the root directory, unmount the file system 87and run 88.Xr fsck 8 89on the file system. 90The bad sectors should show up in two files 91or in the bad sector files and the free list. 92Have 93.Em fsck 94remove files containing the offending bad sectors, but 95.Em do not 96have it remove the 97.Pa BAD/ Ns Em nnnnn 98files. 99This will leave the bad sectors in only the 100.Li BAD 101files. 102.Pp 103.Nm 104works by giving the specified sector numbers in a 105.Xr mknod 2 106system call, 107creating an illegal file whose first block address is the block containing 108the bad sector, and whose name is the bad sector number. 109When it is discovered by 110.Em fsck 111it will ask 112.Dq Li "HOLD BAD BLOCK?" 113A positive response will cause 114.Em fsck 115to convert the inode to a regular file containing the bad block. 116.Sh DIAGNOSTICS 117.Nm 118refuses to attach a block that 119resides in a critical area or is out of range of the file system. 120A warning is issued if the block is already in use. 121.Sh SEE ALSO 122.Xr bad144 8 , 123.Xr fsck 8 124.Sh HISTORY 125The 126.Nm 127command appeared in 128.Bx 4.1 . 129.Sh BUGS 130If more than one sector which comprises a file system fragment is bad, 131you should specify only one of them to 132.Nm badsect , 133as the blocks in the bad sector files actually cover all the sectors in a 134file system fragment. 135