Backup stuck at 280 GB / 1.6 TB (18%) copied

how long should I leave this [Deleted] like this.  its been hours for a 2.7gb file over the USB 3.0 segate 4tb 3.0 enclosure.  

  Also should I eject and retry the backup over?   I dont want to loose the 280gb that already transfered 

Maybe you should try contacting WD’s Technical Support about this. You can do so either by phone or email.

To Contact WD for Technical Support
http://support.wdc.com/contact/index.asp?lang=en

Support by Country
http://support.wdc.com/country/index.asp

Regards,