I am very curious at how did you use your USB 3.0 device. as of this moment, on window 7 GOS, by default, USB 3.0 is not supported, did you install USB 3.0 driver by yourself within window 7 GOS? alternatively, did you configure USB Compatibility as "USB 2.0" in order to use USB 3.0 device?
Unfortunately, I did not reproduce this issue locally with the following steps.
1. Insert one USB 3.0 disk and present it to Window 7 GOS.
2. Configure setttings==>sharing to enable one external device with Thunderport interface.
3. Power on window 7 GOS and copy one 4G big ISO file to "Thunderport" Drivers/Folders without any issue while USB 3.0 has 200M diskspace only.
Based on current information, you supplied, root cause can not be determined. please help answer the following questions and implement the following Action plan.
Questions
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1. only see this issue on one Window 7 GOS or all of GOS.
2. If you remove/unpresent the USB 3.0 Device, coping file sucess?
3. If you remove/unpresent the Thunderport disk, could you copy file to USB 3.0 disk?
Action plan
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1. describe the detailed steps, preferred with one video/screenshot
2. upload support information through Help==>Collect Support Information
Best Regards,
changhai