Why not just use the -v flag of the copy command
You'll need to ensure that the source file is big enough to fill the disk, as well.
Copies one or more files to another location.
COPY [/A | /B] source [/A | /B] [+ source [/A | /B] [+ ...]] [destination
[/A | /B]] [/V] [/N]
source Specifies the file or files to be copied.
/A Indicates an ASCII text file.
/B Indicates a binary file.
destination Specifies the directory and/or filename for the new file(s).
/V Verifies that new files are written correctly.
/N Uses short filename, if available, when copying a file with
/Z Copies networked files in restartable mode.
To append files, specify a single file for destination, but multiple files
for source (using wildcards or file1+file2+file3 format).