1.\" $OpenBSD: badsect.8,v 1.4 1998/09/23 01:20:22 aaron 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. All advertising materials mentioning features or use of this software 16.\" must display the following acknowledgement: 17.\" This product includes software developed by the University of 18.\" California, Berkeley and its contributors. 19.\" 4. Neither the name of the University nor the names of its contributors 20.\" may be used to endorse or promote products derived from this software 21.\" without specific prior written permission. 22.\" 23.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33.\" SUCH DAMAGE. 34.\" 35.\" @(#)badsect.8 8.1 (Berkeley) 6/5/93 36.\" 37.Dd June 5, 1993 38.Dt BADSECT 8 39.Os BSD 4 40.Sh NAME 41.Nm badsect 42.Nd create files to contain bad sectors 43.Sh SYNOPSIS 44.Nm /sbin/badsect 45.Ar bbdir sector Op Ar ... 46.Sh DESCRIPTION 47.Nm badsect 48makes 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; see 51.Xr bad144 8 52for details. 53If a driver supports the bad blocking standard it is much preferable to 54use that method to isolate bad blocks, since the bad block forwarding 55makes the pack appear perfect, and such packs can then be copied with 56.Xr dd 1 . 57The technique used by this program is also less general than 58bad block forwarding, as 59.Nm badsect 60can't make amends for 61bad blocks in the i-list of file systems or in swap areas. 62.Pp 63On some disks, 64adding a sector which is suddenly bad to the bad sector table 65currently requires the running of the standard 66.Tn DEC 67formatter. 68Thus to deal with a newly bad block 69or on disks where the drivers 70do not support the bad-blocking standard 71.Nm badsect 72may be used to good effect. 73.Pp 74.Nm badsect 75is used on a quiet file system in the following way: 76First mount the file system, and change to its root directory. 77Make a directory 78.Li BAD 79there. Run 80.Nm badsect 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 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 badsect 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 108bad sector and whose name is the bad sector number. 109When it is discovered by 110.Xr fsck 111it will ask 112.Dq Li "HOLD BAD BLOCK ?" 113A positive response will cause 114.Xr fsck 115to convert the inode to a regular file containing the bad block. 116.Sh SEE ALSO 117.Xr bad144 8 , 118.Xr format 8 , 119.Xr fsck 8 120.Sh DIAGNOSTICS 121.Nm badsect 122refuses to attach a block that 123resides in a critical area or is out of range of the file system. 124A warning is issued if the block is already in use. 125.Sh BUGS 126If more than one sector which comprise a file system fragment are bad, 127you should specify only one of them to 128.Nm badsect , 129as the blocks in the bad sector files actually cover all the sectors in a 130file system fragment. 131.Sh HISTORY 132The 133.Nm 134command appeared in 135.Bx 4.1 . 136