1.\" $NetBSD: badsect.8,v 1.15 2001/11/16 11:21:38 wiz Exp $ 2.\" 3.\" Copyright (c) 1985, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by the University of 17.\" California, Berkeley and its contributors. 18.\" 4. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.\" @(#)badsect.8 8.1 (Berkeley) 6/5/93 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 46.Nm 47makes a file to contain a bad sector. 48Normally, bad sectors are made inaccessible by the standard formatter, 49which provides a forwarding table for bad sectors to the driver; see 50.Xr bad144 8 51for details. 52If a driver supports the bad blocking standard it is much preferable to 53use that method to isolate bad blocks, since the bad block forwarding 54makes the pack appear perfect, and such packs can then be copied with 55.Xr dd 1 . 56The technique used by this program is also less general than 57bad block forwarding, as 58.Nm 59can't make amends for 60bad blocks in the i-list of file systems or in swap areas. 61.Pp 62On some disks, 63adding a sector which is suddenly bad to the bad sector table 64currently requires the running of the standard 65.Tn DEC 66formatter. 67Thus to deal with a newly bad block 68or on disks where the drivers 69do not support the bad-blocking standard 70.Nm 71may be used to good effect. 72.Pp 73.Nm 74is 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. 85The 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. 92The bad sectors should show up in two files 93or in the bad sector files and the free list. 94Have 95.Xr fsck 8 96remove files containing the offending bad sectors, but 97.Em do not 98have it remove the 99.Pa BAD/ Ns Em nnnnn 100files. 101This will leave the bad sectors in only the 102.Li BAD 103files. 104.Pp 105.Nm 106works by giving the specified sector numbers in a 107.Xr mknod 2 108system call, 109creating an illegal file whose first block address is the block containing 110bad sector and whose name is the bad sector number. 111When it is discovered by 112.Xr fsck 8 113it will ask 114.Dq Li "HOLD BAD BLOCK ?" 115A positive response will cause 116.Xr fsck 8 117to convert the inode to a regular file containing the bad block. 118.Sh DIAGNOSTICS 119.Nm 120refuses 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 bad144 8 , 125.Xr fsck 8 126.Sh HISTORY 127The 128.Nm 129command appeared in 130.Bx 4.1 . 131.Sh BUGS 132If more than one of the sectors in a file system fragment are bad, 133you should specify only one of them to 134.Nm "" , 135as the blocks in the bad sector files actually cover all the sectors in a 136file system fragment. 137