gistfile1.txt

[nix-shell:~]$ sudo dd if=Downloads/NIXOS_SYSTEM.img of=/dev/mmcblk0p2 bs=8M oflag=sync,direct status=progress
1811939328 bytes (1.8 GB, 1.7 GiB) copied, 59 s, 30.7 MB/s 
dd: error writing '/dev/mmcblk0p2': No space left on device
218+0 records in
217+0 records out
1825570816 bytes (1.8 GB, 1.7 GiB) copied, 59.4498 s, 30.7 MB/s

[nix-shell:~]$ du -h Downloads/NIXOS_SYSTEM.img
3.4G	Downloads/NIXOS_SYSTEM.img

[nix-shell:~]$ sudo fdisk -l
...

Disk /dev/mmcblk0: 119.1 GiB, 127865454592 bytes, 249737216 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x01234567

Device         Boot  Start     End Sectors  Size Id Type
/dev/mmcblk0p1 *     22528  284671  262144  128M 83 Linux
/dev/mmcblk0p2      284672 3850239 3565568  1.7G 83 Linux