dd flags & options

if=

Specify the input file to read from.

dd if=/dev/sda of=disk.img

of=

Specify the output file to write to.

dd if=image.iso of=/dev/sdb

bs=

Set both read and write block size.

dd if=/dev/zero of=zeros.bin bs=1M count=100

dd if=/dev/sda of=disk.img bs=4M

count=

Copy only this many input blocks.

dd if=/dev/urandom of=random.bin bs=1K count=512

status=progress

Show periodic transfer statistics during the copy.

dd if=image.iso of=/dev/sdb bs=4M status=progress

conv=fsync

Flush data to disk before finishing to ensure writes are complete.

dd if=image.iso of=/dev/sdb bs=4M conv=fsync status=progress

conv=notrunc

Do not truncate the output file before writing.

dd if=patch.bin of=disk.img bs=1 seek=512 conv=notrunc