My mini Linux primer: the /dev folder contains devices, everything in Linux is a file. Hard drives usually show us as ‘sdX’ which is for serial drives, X being [a, b, c, …] with each letter corresponding to a drive … (old ATA will show up as hda). My sd card shows us as /dev/mmcblk (with each partition having a number like /dev/mmcblk0p1) which is different than the ‘sdX’ naming convension. The output of ‘dmesg | tail’ will show you the most recent drive inserted into your system, find the lettering that corresponds with above.