Pi 3 Restarts (crashes) when Copying Large Files to USB

[TheRoark]

I'm running Kali on my RPI3. When transferring large files to a 128GB USB drive (a good Samsung one), the RPI3 crashes and reboots. In this context, "Large" seems to mean above 100MB. Smaller file transfers are fine and do not crash the Pi. I have tried transferring using (1) the cp command; (2) the rsync command; and (3) the Thunar file browser drag and drop. Each crashes the Pi. Incremental copying of large files using Syncthing do not crash the Pi.

I am buying a new power source, on the hopes it is somehow drawing too much power on the copies. But if not that, any ideas?

[MaxK1]

Why do you think the PSU is to blame? If you aren't seeing the "red power LED" blinking off, that may not be the problem. Does your USB drive have its own power supply? Does 'dmesg' show anything while the file is being copied?

[TheRoark]

The power supply was just a guess because one time I saw the little lightning icon show up during the copy, right before the crash.

The USB is unpowered. Just a thumb drive.

Running dmesg doesn't show anything about the copy after the crash. During the copy, ithe Pi just restarts -- so I can't really see anything.

[rpdom]

The power supply was just a guess because one time I saw the little lightning icon show up during the copy, right before the crash.

That's a pretty good indication that the PSU may well be the problem.

[TheRoark]

Great. Will report back if that is the problem when I get the new supply -- sometime tomorrow.

[TheRoark]

It was the power supply!