- -b
block_size
-
Specify the size of blocks in bytes. The default is 1024.
- -c
number of blocks
-
is the number of blocks which are tested at a time. The default is
64.
- -d
read delay factor
-
This parameter, if passed and non-zero, will cause bad blocks to
sleep between reads if there were no errors encountered in the read
operation; the delay will be calculated as a percentage of the time it
took for the read operation to be performed. In other words, a value of
100 will cause each read to be delayed by the amount the previous read
took, and a value of 200 by twice the amount.
- -e
max bad block count
-
Specify a maximum number of bad blocks before aborting the test. The
default is 0, meaning the test will continue until the end of the test
range is reached.
- -f
-
Normally, badblocks will refuse to do a read/write or a
non-destructive test on a device which is mounted, since either can
cause the system to potentially crash and/or damage the file system even
if it is mounted read-only. This can be overridden using the
-f flag, but should almost never be used --- if you
think you're smarter than the badblocks program, you
almost certainly aren't. The only time when this option might be safe to
use is if the /etc/mtab file is incorrect, and the device really isn't
mounted.
- -i
input_file
-
Read a list of already existing known bad blocks.
Badblocks will skip testing these blocks since they are
known to be bad. If input_file is specified as "-", the list
will be read from the standard input. Blocks listed in this list will be
omitted from the list of new bad blocks produced on the
standard output or in the output file. The -b option of
dumpe2fs(8) can be used to retrieve the list of blocks
currently marked bad on an existing file system, in a format suitable
for use with this option.
- -n
-
Use non-destructive read-write mode. By default only a
non-destructive read-only test is done. This option must not be combined
with the -w option, as they are mutually exclusive.
- -o
output_file
-
Write the list of bad blocks to the specified file. Without this
option, badblocks displays the list on its standard
output. The format of this file is suitable for use by the
-l option in e2fsck(8) or
mke2fs(8).
- -p
num_passes
-
Repeat scanning the disk until there are no new blocks discovered in
num_passes consecutive scans of the disk. Default is 0, meaning
badblocks will exit after the first pass.
- -s
-
Show the progress of the scan by writing out rough percentage
completion of the current badblocks pass over the disk. Note that
badblocks may do multiple test passes over the disk, in particular if
the -p or -w option is requested by
the user.
- -t
test_pattern
-
Specify a test pattern to be read (and written) to disk blocks. The
test_pattern may either be a numeric value between 0 and
ULONG_MAX-1 inclusive, or the word "random", which specifies that the
block should be filled with a random bit pattern. For read/write
(-w) and non-destructive (-n) modes,
one or more test patterns may be specified by specifying the
-t option for each test pattern desired. For read-only
mode only a single pattern may be specified and it may not be "random".
Read-only testing with a pattern assumes that the specified pattern has
previously been written to the disk - if not, large numbers of blocks
will fail verification. If multiple patterns are specified then all
blocks will be tested with one pattern before proceeding to the next
pattern.
- -v
-
Verbose mode. Will write the number of read errors, write errors and
data- corruptions to stderr.
- -w
-
Use write-mode test. With this option, 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. This option may not be combined with the -n
option, as they are mutually exclusive.
- -B
-
Use buffered I/O and do not use Direct I/O, even if it is
available.
- -X
-
Internal flag only to be used by e2fsck(8) and
mke2fs(8). It bypasses the exclusive mode in-use device
safety check.