usr/src/sbin/badsect/badsect.8

.\" Copyright (c) 1985 The Regents of the University of California.
.\" All rights reserved.
.\"
.\" %sccs.include.redist.man%
.\"
.\"	@(#)badsect.8	6.3 (Berkeley) %G%
.\"
.TH BADSECT 8 ""
.UC 4
.SH NAME
badsect \- create files to contain bad sectors
.SH SYNOPSIS
.B /etc/badsect
bbdir sector ...
.SH DESCRIPTION
.I 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
.IR 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
.IR dd (1).
The technique used by this program is also less general than
bad block forwarding, as
.I 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 DEC formatter.
Thus to deal with a newly bad block
or on disks where the drivers
do not support the bad-blocking standard
.I badsect
may be used to good effect.
.PP
.I 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 BAD there.  Run
.I badsect
giving as argument the 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
.IR 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
.I fsck
remove files containing the offending bad sectors, but
.B "do not"
have it remove the BAD/\fInnnnn\fR files.
This will leave the bad sectors in only the BAD files.
.PP
.I Badsect
works by giving the specified sector numbers in a
.IR 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
.I fsck
it will ask ``HOLD BAD BLOCK''?
A positive response will cause
.I fsck
to convert the inode to a regular file containing the bad block.
.SH SEE ALSO
bad144(8),
fsck(8),
format(8V)
.SH DIAGNOSTICS
.I 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
.I badsect,
as the blocks in the bad sector files actually cover all the sectors in a
file system fragment.
Commit	Line	Data
	1	.\" Copyright (c) 1985 The Regents of the University of California.
	2	.\" All rights reserved.
	3	.\"
	4	.\" %sccs.include.redist.man%
	5	.\"
	6	.\" @(#)badsect.8 6.3 (Berkeley) %G%
	7	.\"
	8	.TH BADSECT 8 ""
	9	.UC 4
	10	.SH NAME
	11	badsect \- create files to contain bad sectors
	12	.SH SYNOPSIS
	13	.B /etc/badsect
	14	bbdir sector ...
	15	.SH DESCRIPTION
	16	.I Badsect
	17	makes a file to contain a bad sector. Normally, bad sectors
	18	are made inaccessible by the standard formatter, which provides
	19	a forwarding table for bad sectors to the driver; see
	20	.IR bad144 (8)
	21	for details.
	22	If a driver supports the bad blocking standard it is much preferable to
	23	use that method to isolate bad blocks, since the bad block forwarding
	24	makes the pack appear perfect, and such packs can then be copied with
	25	.IR dd (1).
	26	The technique used by this program is also less general than
	27	bad block forwarding, as
	28	.I badsect
	29	can't make amends for
	30	bad blocks in the i-list of file systems or in swap areas.
	31	.PP
	32	On some disks,
	33	adding a sector which is suddenly bad to the bad sector table
	34	currently requires the running of the standard DEC formatter.
	35	Thus to deal with a newly bad block
	36	or on disks where the drivers
	37	do not support the bad-blocking standard
	38	.I badsect
	39	may be used to good effect.
	40	.PP
	41	.I Badsect
	42	is used on a quiet file system in the following way:
	43	First mount the file system, and change to its root directory.
	44	Make a directory BAD there. Run
	45	.I badsect
	46	giving as argument the BAD directory followed by
	47	all the bad sectors you wish to add.
	48	(The sector numbers must be relative to the beginning of
	49	the file system, but this is not hard as the system reports
	50	relative sector numbers in its console error messages.)
	51	Then change back to the root directory, unmount the file system
	52	and run
	53	.IR fsck (8)
	54	on the file system. The bad sectors should show up in two files
	55	or in the bad sector files and the free list. Have
	56	.I fsck
	57	remove files containing the offending bad sectors, but
	58	.B "do not"
	59	have it remove the BAD/\fInnnnn\fR files.
	60	This will leave the bad sectors in only the BAD files.
	61	.PP
	62	.I Badsect
	63	works by giving the specified sector numbers in a
	64	.IR mknod (2)
	65	system call,
	66	creating an illegal file whose first block address is the block containing
	67	bad sector and whose name is the bad sector number.
	68	When it is discovered by
	69	.I fsck
	70	it will ask ``HOLD BAD BLOCK''?
	71	A positive response will cause
	72	.I fsck
	73	to convert the inode to a regular file containing the bad block.
	74	.SH SEE ALSO
	75	bad144(8),
	76	fsck(8),
	77	format(8V)
	78	.SH DIAGNOSTICS
	79	.I Badsect
	80	refuses to attach a block that
	81	resides in a critical area or is out of range of the file system.
	82	A warning is issued if the block is already in use.
	83	.SH BUGS
	84	If more than one sector which comprise a file system fragment are bad,
	85	you should specify only one of them to
	86	.I badsect,
	87	as the blocks in the bad sector files actually cover all the sectors in a
	88	file system fragment.