.\" -*- nroff -*-
.TH BADBLOCKS 8 "@E2FSPROGS_MONTH@ @E2FSPROGS_YEAR@" "E2fsprogs version @E2FSPROGS_VERSION@"
.SH NAME
badblocks \- search a device for bad blocks
.SH SYNOPSIS
.B badblocks
[
.B \-svwn
]
[
.B \-b
.I block-size
]
[
.B \-c
.I blocks_at_once
]
[
.B \-i
.I input_file
]
[
.B \-o
.I output_file
]
[
.B \-p
.I num_passes
]
.I device
.IR blocks-count [ start-block ]
.SH DESCRIPTION
.B badblocks
is used to search for bad blocks on a device (usually a disk partition).
.I device
is the special file corresponding to the device (e.g
.IR /dev/hdc1 ).
.I blocks-count
is the number of blocks on the device.
.SH OPTIONS
.TP
.BI \-b " block-size"
Specify the size of blocks in bytes.
.TP
.BI \-c " number of blocks"
is the number of blocks which are tested at a time.  The default is 16.
.TP
.BI \-i " input_file"
Read a list of already existing known bad blocks.  Badblocks will skip 
testing these blocks since they are known bad.
.TP
.BI \-o " output_file"
Write the list of bad blocks to the specified file.  Without this option,
.B badblocks
displays the list on its standard output.  The format of this file is suitable
for use by the
.
.B \-l
option in 
.BR e2fsck (8)
or
.BR mke2fs (8).
.TP
.BI \-p " num_passes"
Repeat scanning the disk until there are no new blocks discovered after
num_passes scans of the disk.
.TP
.B \-n
Use non-destructive read-write mode.
.TP
.B \-s
Show the progress of the scan by writing out the block numbers as they
are checked.
.TP
.B \-v
Verbose mode.
.TP
.B \-w
Use write-mode test. With this option,
.B badblocks
scans for bad blocks by writing some patterns (0xaa, 0x55, 0xff, 0x00) on
every block of the device, reading every block and comparing the contents.
.SH WARNING
Never use the
.B \-w
option on an device containing an existing file system.
This option erases data!
.SH AUTHOR
.B badblocks
was written by Remy Card <Remy.Card@linux.org>.  Current maintainer is
Theodore Ts'o <tytso@alum.mit.edu>.  Non-destructive read/write test
implemented by David Beattie <dbeattie@usa.net>.
.SH AVAILABILITY
.B badblocks
is part of the e2fsprogs package and is available for anonymous 
ftp from tsx-11.mit.edu in /pub/linux/packages/ext2fs.
.SH SEE ALSO
.BR e2fsck (8),
.BR mke2fs (8)