check finishes, transfers begin cranking fairly well, at some point the machine grinds to a halt and eventually kernel panics and reboots (on the windows side it was the windows 10 version of a BSOD)
I'm about to fire up a different machine (a Thinkpad) to see what happens, but in all my years of using qnap I realized I never actually used it with an external local drive. could be this external is dying in some way... I don't know.. just wondering what others may have experienced lately in this scenario.
Can be anything really with very unlikely chances that it is caused by rclone. If your OS panics (BSOD) than there is something seriously wrong with either your hardware or OS installation itself.
I would normally agree but nothing else is even remotely stressing the system, it's only when I initiate this large transfer does the system spiral out of control is my point. it's more symptom/vs cause
You are real pushing things hard with the above settings. Clearly your machine can not cope with it and have some faulty hardware or buggy kernel level software component as normally OS should not die but gracefully kill whatever is causing problems - like OOM.
Can be SMB windows driver, can be RAM, overheated CPU and who knows what else. Very often it is caused by 3rd party software - maybe your network card driver which can not handle sustained high level traffic?
Run your sync with much lower values which will stress everything much less.
And in terms of BSOD Windows should generate some log or dump where you can investigate what is bringing all OS down. I am not Windows user so can't give you more details.