1.\" $NetBSD: badsect.8,v 1.17 2003/08/07 10:04:11 agc 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. Neither the name of the University nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.\" @(#)badsect.8 8.1 (Berkeley) 6/5/93 31.\" 32.Dd June 5, 1993 33.Dt BADSECT 8 34.Os 35.Sh NAME 36.Nm badsect 37.Nd create files to contain bad sectors 38.Sh SYNOPSIS 39.Nm 40.Ar bbdir sector ... 41.Sh DESCRIPTION 42.Nm 43makes a file to contain a bad sector. 44Normally, bad sectors are made inaccessible by the standard formatter, 45which provides a forwarding table for bad sectors to the driver; see 46.Xr bad144 8 47for details. 48If a driver supports the bad blocking standard it is much preferable to 49use that method to isolate bad blocks, since the bad block forwarding 50makes the pack appear perfect, and such packs can then be copied with 51.Xr dd 1 . 52The technique used by this program is also less general than 53bad block forwarding, as 54.Nm 55can't make amends for 56bad blocks in the i-list of file systems or in swap areas. 57.Pp 58On some disks, 59adding a sector which is suddenly bad to the bad sector table 60currently requires the running of the standard 61.Tn DEC 62formatter. 63Thus to deal with a newly bad block 64or on disks where the drivers 65do not support the bad-blocking standard 66.Nm 67may be used to good effect. 68.Pp 69.Nm 70is used on a quiet file system in the following way: 71First mount the file system, and change to its root directory. 72Make a directory 73.Li BAD 74there. 75Run 76.Nm 77giving as argument the 78.Ar BAD 79directory followed by 80all the bad sectors you wish to add. 81The sector numbers must be relative to the beginning of 82the file system, but this is not hard as the system reports 83relative sector numbers in its console error messages. 84Then change back to the root directory, unmount the file system 85and run 86.Xr fsck 8 87on the file system. 88The bad sectors should show up in two files 89or in the bad sector files and the free list. 90Have 91.Xr fsck 8 92remove files containing the offending bad sectors, but 93.Em do not 94have it remove the 95.Pa BAD/ Ns Em nnnnn 96files. 97This will leave the bad sectors in only the 98.Li BAD 99files. 100.Pp 101.Nm 102works by giving the specified sector numbers in a 103.Xr mknod 2 104system call, 105creating an illegal file whose first block address is the block containing 106bad sector and whose name is the bad sector number. 107When it is discovered by 108.Xr fsck 8 109it will ask 110.Dq Li "HOLD BAD BLOCK ?" 111A positive response will cause 112.Xr fsck 8 113to convert the inode to a regular file containing the bad block. 114.Sh DIAGNOSTICS 115.Nm 116refuses to attach a block that 117resides in a critical area or is out of range of the file system. 118A warning is issued if the block is already in use. 119.Sh SEE ALSO 120.Xr bad144 8 , 121.Xr fsck 8 122.Sh HISTORY 123The 124.Nm 125command appeared in 126.Bx 4.1 . 127.Sh BUGS 128If more than one of the sectors in a file system fragment are bad, 129you should specify only one of them to 130.Nm , 131as the blocks in the bad sector files actually cover all the sectors in a 132file system fragment. 133