Robocopy falsely marks files as newer
We found that using the /FFT Robocopy switch will reduce the timestamp to about 2 seconds difference when comparing file changes. It eliminated the 2 hours copying everything when the changed files would normaly take under 3 minutes.
RoboCopy /?
says to use this switch to "assume FAT File Times (2-second granularity)."
Thanks to the folks at connetrix.
http://www.conetrix.com/Blog/post/Robocopy-Incorrectly-Detects-Files-as-Newer-When-Copying-Between-Different-File-Systems.aspx
Try this:
robocopy "D:\My Documents" "X:\Backup\My Documents" /FFT /MIR /V /NP /XD .* /XO /XA:SHTO /FAT /Z /ETA /DST /R:3 /W:30
It worked for us.