dd — Convert and Copy Files

October 15, 2026September 15, 2005 by Gaurav Masand

dd copies data at a low level. It is powerful, but it can overwrite disks if the input and output paths are wrong.

Create an image of a disk or partition

dd if=/dev/sdb of=disk-image.img bs=4M status=progress

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

Always double-check the target device before running dd. A wrong of= value can destroy data.

lsblk