Did the target directory dir2 already exist?
Also the way you reference dir2 it may have been created, or attempted to, subordinate to where the server was running. Which may not be quite where you think. And a similar issue exists with the source directory.
It is usually a good idea to include the root directory or mount point as the start of file paths.
You may also need to incorporate the /T switch if the directory structure doesn't already exist.