tldr/pages/linux/dd.md

dd

Convert and copy a file. More information: https://www.gnu.org/software/coreutils/dd.

• Make a bootable USB drive from an isohybrid file (such as archlinux-xxx.iso) and show the progress:

dd status=progress if={{path/to/file.iso}} of={{/dev/usb_drive}}

• Clone a drive to another drive with 4 MiB block size and flush writes before the command terminates:

dd bs={{4M}} conv={{fsync}} if={{/dev/source_drive}} of={{/dev/dest_drive}}

• Generate a file with a specific number of random bytes by using kernel random driver:

dd bs={{100}} count={{1}} if=/dev/urandom of={{path/to/random_file}}

• Benchmark the write performance of a disk:

dd bs={{1M}} count={{1000000}} if=/dev/zero of={{path/to/file_1GB}}

• Create a system backup and save it into an IMG file (can be restored later by swapping if and of):

dd if={{/dev/drive_device}} of={{path/to/file.img}}

• Check the progress of an ongoing dd operation (run this command from another shell):

kill -USR1 $(pgrep -x dd)