[unix-history] / usr / src / sbin / badsect / badsect.8

.\" Copyright (c) 1985, 1991 The Regents of the University of California.
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by the University of
.\"	California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"     @(#)badsect.8	6.4 (Berkeley) 3/16/91
.\"
.Dd March 16, 1991
.Dt BADSECT 8
.Os BSD 4
.Sh NAME
.Nm badsect
.Nd create files to contain bad sectors
.Sh SYNOPSIS
.Nm /etc/badsect
.Ar bbdir sector ...
.Sh DESCRIPTION
.Nm Badsect
makes a file to contain a bad sector.  Normally, bad sectors
are made inaccessible by the standard formatter, which provides
a forwarding table for bad sectors to the driver; see
.Xr bad144 8
for details.
If a driver supports the bad blocking standard it is much preferable to
use that method to isolate bad blocks, since the bad block forwarding
makes the pack appear perfect, and such packs can then be copied with
.Xr dd 1 .
The technique used by this program is also less general than
bad block forwarding, as
.Nm badsect
can't make amends for
bad blocks in the i-list of file systems or in swap areas.
.Pp
On some disks,
adding a sector which is suddenly bad to the bad sector table
currently requires the running of the standard
.Tn DEC
formatter.
Thus to deal with a newly bad block
or on disks where the drivers
do not support the bad-blocking standard 
.Nm badsect
may be used to good effect.
.Pp
.Nm Badsect
is used on a quiet file system in the following way:
First mount the file system, and change to its root directory.
Make a directory
.Li BAD
there.  Run
.Nm badsect
giving as argument the
.Ar BAD
directory followed by
all the bad sectors you wish to add.
(The sector numbers must be relative to the beginning of
the file system, but this is not hard as the system reports
relative sector numbers in its console error messages.)
Then change back to the root directory, unmount the file system
and run
.Xr fsck 8
on the file system.  The bad sectors should show up in two files
or in the bad sector files and the free list.  Have
.Xr fsck
remove files containing the offending bad sectors, but 
.Em do not
have it remove the
.Pa BAD/ Ns Em nnnnn
files.
This will leave the bad sectors in only the
.Li BAD
files.
.Pp
.Nm Badsect
works by giving the specified sector numbers in a
.Xr mknod 2
system call,
creating an illegal file whose first block address is the block containing
bad sector and whose name is the bad sector number.
When it is discovered by 
.Xr fsck
it will ask
.Dq Li "HOLD BAD BLOCK ?"
A positive response will cause 
.Xr fsck
to convert the inode to a regular file containing the bad block.
.Sh SEE ALSO
.Xr bad144 8 ,
.Xr fsck 8 ,
.Xr format 8
.Sh DIAGNOSTICS
.Nm Badsect
refuses to attach a block that
resides in a critical area or is out of range of the file system.
A warning is issued if the block is already in use.
.Sh BUGS
If more than one sector which comprise a file system fragment are bad,
you should specify only one of them to
.Nm badsect ,
as the blocks in the bad sector files actually cover all the sectors in a
file system fragment.
.Sh HISTORY
The
.Nm
command appeared in
.Bx 4.1 .
Commit	Line	Data
f81b4636 WJ	1	.\" Copyright (c) 1985, 1991 The Regents of the University of California.
	2	.\" 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 acknowledgement:
	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 6.4 (Berkeley) 3/16/91
	33	.\"
	34	.Dd March 16, 1991
	35	.Dt BADSECT 8
	36	.Os BSD 4
	37	.Sh NAME
	38	.Nm badsect
	39	.Nd create files to contain bad sectors
	40	.Sh SYNOPSIS
	41	.Nm /etc/badsect
	42	.Ar bbdir sector ...
	43	.Sh DESCRIPTION
	44	.Nm Badsect
	45	makes a file to contain a bad sector. Normally, bad sectors
	46	are made inaccessible by the standard formatter, which provides
	47	a forwarding table for bad sectors to the driver; see
	48	.Xr bad144 8
	49	for details.
	50	If a driver supports the bad blocking standard it is much preferable to
	51	use that method to isolate bad blocks, since the bad block forwarding
	52	makes the pack appear perfect, and such packs can then be copied with
	53	.Xr dd 1 .
	54	The technique used by this program is also less general than
	55	bad block forwarding, as
	56	.Nm badsect
	57	can't make amends for
	58	bad blocks in the i-list of file systems or in swap areas.
	59	.Pp
	60	On some disks,
	61	adding a sector which is suddenly bad to the bad sector table
	62	currently requires the running of the standard
	63	.Tn DEC
	64	formatter.
65	Thus to deal with a newly bad block
66	or on disks where the drivers
67	do not support the bad-blocking standard
68	.Nm badsect
69	may be used to good effect.
70	.Pp
71	.Nm Badsect
72	is used on a quiet file system in the following way:
73	First mount the file system, and change to its root directory.
74	Make a directory
75	.Li BAD
76	there. Run
77	.Nm badsect
78	giving as argument the
79	.Ar BAD
80	directory followed by
81	all the bad sectors you wish to add.
82	(The sector numbers must be relative to the beginning of
83	the file system, but this is not hard as the system reports
84	relative sector numbers in its console error messages.)
85	Then change back to the root directory, unmount the file system
86	and run
87	.Xr fsck 8
88	on the file system. The bad sectors should show up in two files
89	or in the bad sector files and the free list. Have
90	.Xr fsck
91	remove files containing the offending bad sectors, but
92	.Em do not
93	have it remove the
94	.Pa BAD/ Ns Em nnnnn
95	files.
96	This will leave the bad sectors in only the
97	.Li BAD
98	files.
99	.Pp
100	.Nm Badsect
101	works by giving the specified sector numbers in a
102	.Xr mknod 2
103	system call,
104	creating an illegal file whose first block address is the block containing
105	bad sector and whose name is the bad sector number.
106	When it is discovered by
107	.Xr fsck
108	it will ask
109	.Dq Li "HOLD BAD BLOCK ?"
110	A positive response will cause
111	.Xr fsck
112	to convert the inode to a regular file containing the bad block.
113	.Sh SEE ALSO
114	.Xr bad144 8 ,
115	.Xr fsck 8 ,
116	.Xr format 8
117	.Sh DIAGNOSTICS
118	.Nm Badsect
119	refuses to attach a block that
120	resides in a critical area or is out of range of the file system.
121	A warning is issued if the block is already in use.
122	.Sh BUGS
123	If more than one sector which comprise a file system fragment are bad,
124	you should specify only one of them to
125	.Nm badsect ,
126	as the blocks in the bad sector files actually cover all the sectors in a
127	file system fragment.
128	.Sh HISTORY
129	The
130	.Nm
131	command appeared in
132	.Bx 4.1 .