During Windows backup, which wants to backup the 'C' drive and my games drive 'E' (for some reason), I get the following error message after the 'C' backup has completed but not the 'E':

'The backup operation that started at '‎2015‎-‎12‎-‎20T06:00:25.459859400Z' has failed with following error code '0x8078012D' (The operation failed due to a device error encountered with either the source or the destination. If the source or destination volume is on a disk, run CHKDSK /R on the source or destination volume, and then retry the operation.). Please review the event details for a solution, and then rerun the backup operation once the issue is resolved.'

I ran CHKDSK \R and received several errors of the type: 'A disk read error occurred 0000185. The disk does not have enough space to replace bad clusters detected in file xxxxxx of name xxxxxx.'

My 'E' drive is 2TB with 205GB free. I really don't believe that the cluster(s) in error are bigger than 205G, but what do I know?

Anyone have experience with this problem?