1.\" Copyright (c) 1985, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgment: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)badsect.8 8.1 (Berkeley) 6/5/93 33.\" $FreeBSD: src/sbin/badsect/badsect.8,v 1.10.2.6 2002/08/21 18:58:06 trhodes Exp $ 34.\" $DragonFly: src/sbin/badsect/badsect.8,v 1.4 2006/04/08 08:17:07 swildner Exp $ 35.\" 36.Dd June 5, 1993 37.Dt BADSECT 8 38.Os 39.Sh NAME 40.Nm badsect 41.Nd create files to contain bad sectors 42.Sh SYNOPSIS 43.Nm 44.Ar bbdir sector ... 45.Sh DESCRIPTION 46The 47.Nm 48utility makes a file to contain a bad sector. Normally, bad sectors 49are made inaccessible by the standard formatter, which provides 50a forwarding table for bad sectors to the driver. 51If a driver supports the bad blocking standard it is much preferable to 52use that method to isolate bad blocks, since the bad block forwarding 53makes the pack appear perfect, and such packs can then be copied with 54.Xr dd 1 . 55The technique used by this program is also less general than 56bad block forwarding, as 57.Nm 58can't make amends for 59bad blocks in the i-list of file systems or in swap areas. 60.Pp 61On some disks, 62adding a sector which is suddenly bad to the bad sector table 63currently requires the running of the standard 64.Tn DEC 65formatter. 66Thus to deal with a newly bad block 67or on disks where the drivers 68do not support the bad-blocking standard 69.Nm 70may be used to good effect. 71.Pp 72The 73.Nm 74utility is used on a quiet file system in the following way: 75First mount the file system, and change to its root directory. 76Make a directory 77.Li BAD 78there. 79Run 80.Nm 81giving as argument the 82.Ar BAD 83directory followed by 84all the bad sectors you wish to add. 85(The sector numbers must be relative to the beginning of 86the file system, but this is not hard as the system reports 87relative sector numbers in its console error messages.) 88Then change back to the root directory, unmount the file system 89and run 90.Xr fsck 8 91on the file system. The bad sectors should show up in two files 92or in the bad sector files and the free list. Have 93.Xr fsck 8 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 103The 104.Nm 105utility works by giving the specified sector numbers in a 106.Xr mknod 2 107system call, 108creating an illegal file whose first block address is the block containing 109bad sector and whose name is the bad sector number. 110When it is discovered by 111.Xr fsck 8 112it will ask 113.Dq Li "HOLD BAD BLOCK \&?" . 114A positive response will cause 115.Xr fsck 8 116to convert the inode to a regular file containing the bad block. 117.Sh DIAGNOSTICS 118The 119.Nm 120utility refuses to attach a block that 121resides in a critical area or is out of range of the file system. 122A warning is issued if the block is already in use. 123.Sh SEE ALSO 124.Xr fsck 8 125.Sh HISTORY 126The 127.Nm 128utility appeared in 129.Bx 4.1 . 130.Sh BUGS 131If more than one sector which comprise a file system fragment are bad, 132you should specify only one of them to 133.Nm , 134as the blocks in the bad sector files actually cover all the sectors in a 135file system fragment. 136