Suppose I have a directory structure like
```
├── src
│ ├── folder_a
│ │ ├── file_w
│ │ ├── file_x
│ ├── folder_b
│ │ ├── file_y
│ │ ├── file_z
```
and I back it up using `rsync`:
```
$ rsync -r /path/to/src/ /path/to/dst/
```
Later, I reorganize the contents of `src`, for example:
```
├── src
│ ├── folder_c
│ │ ├── file_w
│ │ ├── file_y
│ ├── folder_d
│ │ ├── file_x
│ │ ├── file_z
```
Each file with a given name has not changed; but they don't have the same hierarchical relationship (i.e., files that used to be siblings might not be any more), and the names of their containing folders may have changed.
Can `rsync` detect that the `dst` folder contains the same files, and avoid copying files (instead only moving files within `dst` and renaming folders)? What options are useful to make this as smooth as possible?
