I burned the system into 120g nvme through the sdk manager, and adjusted the environment internally. The system usage was also reduced to less than 14G. Now I want to build the system in nvme into a mirror and burn it to emmc.
./tools/backup_restore/l4t_backup_restore.sh -e nvme0n1 -b jetson-xavier-nx-devkit-emmc # i got emmc image from execute that code
./tools/backup_restore/l4t_backup_restore.sh -e mmcblk0 -r jetson-xavier-nx-devkit-emmc # but i cant flush emmc from emmc image