Backing up system.img from nVME on Xavier NX

Hi,

Flash.sh is not able to touch anything on external drive. Just like it cannot directly flash anything to your external drive.

Initrd flash tool may help here.

https://docs.nvidia.com/jetson/l4t/index.html#page/Tegra%20Linux%20Driver%20Package%20Development%20Guide/flashing.html#wwpID0E0PI0HA