I was using a small USB drive, barely bigger than the USB port, hardly stuck out. Was made by sandisk I think. Lots of corrupted empty files. Sometimes it worked, sometimes it did not. Was certain it was a problem with the Tesla software. It was only 32GB and filling up quickly.
I decided I wanted something bigger and then went to a raspberry pi with a 64 GB micro sandisk card(sandisk endurance), running teslaUSB. I stopped getting the 0 length files, but Tesla would cut the power to the USB ports at bad times, throwing off the operation/reliability.
The I switched to a mini USB reader that holds the 64 GB micro SD card. That works much better. No issues, except sometimes the clip will start out green.