Rrc: Página creada con 'NOTOC * dd == dd == [rrc@Llawyr ComandosDeLaTerminal]$ dd --help Usage: dd [OPERAND]... or: dd OPTION Copy a file, converting ...'

2014-05-17T15:53:50Z

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__NOTOC__
* [[:#dd | dd]]

== dd ==

<syntaxhighlight lang="bash">

[rrc@Llawyr ComandosDeLaTerminal]$ dd --help
Usage: dd [OPERAND]...
or: dd OPTION
Copy a file, converting and formatting according to the operands.

bs=BYTES read and write up to BYTES bytes at a time
cbs=BYTES convert BYTES bytes at a time
conv=CONVS convert the file as per the comma separated symbol list
count=N copy only N input blocks
ibs=BYTES read up to BYTES bytes at a time (default: 512)
if=FILE read from FILE instead of stdin
iflag=FLAGS read as per the comma separated symbol list
obs=BYTES write BYTES bytes at a time (default: 512)
of=FILE write to FILE instead of stdout
oflag=FLAGS write as per the comma separated symbol list
seek=N skip N obs-sized blocks at start of output
skip=N skip N ibs-sized blocks at start of input
status=WHICH WHICH info to suppress outputting to stderr;
'noxfer' suppresses transfer stats, 'none' suppresses all

N and BYTES may be followed by the following multiplicative suffixes:
c =1, w =2, b =512, kB =1000, K =1024, MB =1000*1000, M =1024*1024, xM =M
GB =1000*1000*1000, G =1024*1024*1024, and so on for T, P, E, Z, Y.

Each CONV symbol may be:

ascii from EBCDIC to ASCII
ebcdic from ASCII to EBCDIC
ibm from ASCII to alternate EBCDIC
block pad newline-terminated records with spaces to cbs-size
unblock replace trailing spaces in cbs-size records with newline
lcase change upper case to lower case
ucase change lower case to upper case
sparse try to seek rather than write the output for NUL input blocks
swab swap every pair of input bytes
sync pad every input block with NULs to ibs-size; when used
with block or unblock, pad with spaces rather than NULs
excl fail if the output file already exists
nocreat do not create the output file
notrunc do not truncate the output file
noerror continue after read errors
fdatasync physically write output file data before finishing
fsync likewise, but also write metadata

Each FLAG symbol may be:

append append mode (makes sense only for output; conv=notrunc suggested)
direct use direct I/O for data
directory fail unless a directory
dsync use synchronized I/O for data
sync likewise, but also for metadata
fullblock accumulate full blocks of input (iflag only)
nonblock use non-blocking I/O
noatime do not update access time
nocache discard cached data
noctty do not assign controlling terminal from file
nofollow do not follow symlinks
count_bytes treat 'count=N' as a byte count (iflag only)
skip_bytes treat 'skip=N' as a byte count (iflag only)
seek_bytes treat 'seek=N' as a byte count (oflag only)

Sending a USR1 signal to a running 'dd' process makes it
print I/O statistics to standard error and then resume copying.

$ dd if=/dev/zero of=/dev/null& pid=$!
$ kill -USR1 $pid; sleep 1; kill $pid
18335302+0 records in
18335302+0 records out
9387674624 bytes (9.4 GB) copied, 34.6279 seconds, 271 MB/s

Options are:

--help display this help and exit
--version output version information and exit

Report dd bugs to bug-coreutils@gnu.org
GNU coreutils home page: <http://www.gnu.org/software/coreutils/>
General help using GNU software: <http://www.gnu.org/gethelp/>
For complete documentation, run: info coreutils 'dd invocation'

[rrc@Llawyr ComandosDeLaTerminal]$ dd --version
dd (coreutils) 8.21
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Written by Paul Rubin, David MacKenzie, and Stuart Kemp.

Respaldar el MBR con dd:

MBR Tomaño Total

446 + 64 + 2 = 512

donde,

446 bytes - Bootstrap.
64 bytes - Tabla de Partición.
2 bytes - Firma.

512 vs 446 Bytes

Usa 446 bytes para sobre escribir o restorar tu /dev/XYZ MBR código de boot solo con los contenidos de tu archive de MBR.DD.
Usa 512 bytes para sobre escribir o restorar tu /dev/XYZ con el MBR total que tiene Código de boot, la Tabla de Partición y la firma.

dd comando para copiar MBR (entre solo dos discos con particiones identicales)

dd if=/dev/sda of=/dev/sdb bs=512 count=1
El comando va a copiar 512 bytes (MBR) de sda a sdb. SOLO sirve si los discos tienen particiones identicales.

dd comando para dos discos de particiones de diferentes tomaños

dd if=/dev/sda of=/tmp/mbrsda.bak bs=512 count=1
para restorar el imagen a cualquier sdb:
dd if=/tmp/mbrsda.bak of=/dev/sdb bs=446 count=1

dd comando para creatr un boot USB de un ISO hybrido imagen
dd bs=5M if=NombreDelImage.iso of=/dev/sdx
Debe asegurar que la lave USB NO está monteado

Para vaciar y limpiar un MBR:
dd if=/dev/zero of=/dev/hda bs=512 count=1

</syntaxhighlight>

[[Category:Comandos de la terminal]]

Comandos de la terminal/dd - Historial de revisiones

Rrc: Página creada con '__NOTOC__ * dd == dd == [rrc@Llawyr ComandosDeLaTerminal]$ dd --help Usage: dd [OPERAND]... or: dd OPTION Copy a file, converting ...'

Rrc: Página creada con 'NOTOC * dd == dd == [rrc@Llawyr ComandosDeLaTerminal]$ dd --help Usage: dd [OPERAND]... or: dd OPTION Copy a file, converting ...'