dd#
dd is a tool used for copying and converting data. It operates on blocks of data, and its behavior can be customized
with various operands. It is often used for tasks such as backing up and restoring entire
partitions, copying regions of raw device files, and converting data formats.
Usage#
dd [OPERAND]...
Operands#
if=FILE: Read from FILE instead of standard input.of=FILE: Write to FILE instead of standard output.bs=BYTES: Set both input and output block size to BYTES.count=N: Copy only N input blocks.seek=N: Skip N output blocks before writing.skip=N:Skip N input blocks before reading.conv=CONVS: Apply one or more comma-separated conversions.
Conversions#
nocreat: Do not create the output file.notrunc: Do not truncate the output file.
Examples#
Copy a file with a specific block size:
dd if=input.txt of=output.txt bs=1M
Create a disk image:
dd if=/dev/sda of=disk.img bs=4M
Convert and copy data with no truncation
dd if=input.dat of=output.dat conv=notrunc