Transfer data from SD card to OTG USB - Galaxy S7E v7.0

A

AC Question

I'm about to embark on a cycling trip and need to transfer data from my video camera to a portable USB drive each day.

I'm travelling light so won't be taking a laptop. My plan was to take the micro-sd card out of my camera, put it in my phone, connect a USB drive to my phone via OTG and transfer the content.

Good idea in theory but I'm running into permissions issues when trying to transfer data. I'm reading that I may need to root my pen to be able to do this, can anyone confirm this is still the case please?

Thanks in advance