Robocopy Exit Codes

Error Levels

Value	Description
0	No files were copied. No failure was encountered. No files were mismatched. The files already exist in the destination directory; therefore, the copy operation was skipped.
1	All files were copied successfully.
2	There are some additional files in the destination directory that are not present in the source directory. No files were copied.
3	Some files were copied. Additional files were present. No failure was encountered.
5	Some files were copied. Some files were mismatched. No failure was encountered.
6	Additional files and mismatched files exist. No files were copied and no failures were encountered. This means that the files already exist in the destination directory.
7	Files were copied, a file mismatch was present, and additional files were present.
8	Several files did not copy.

Reference

https://support.microsoft.com/en-us/kb/954404