How to create an exact copy of a USB (bootable, worth LINUX) to another USB in ***.img?

Question

linux

Hello everyone. The essence of the problem is this. There is a NAS QNAP, I want to make a copy of the DOM. DOM is essentially a regular bootable 10pin USB flash drive that is inserted directly into MB)
DOM has several partitions:
/dev/sda1 (boot)
/dev/sda2
/dev/sda3
/dev/sda4 (ext)
/dev/sda5
/dev/sda6
you need to create an image file in the *.img format on the flash drive /dev/sdb

tried clonezila, but for some reason it does not save in img (most likely I'm doing something wrong, level nix is ​​still low =)

Answer 1

You can create a copy using dd
dd if=/dev/sda of=name.img