This is rclone checking files in the destination only (default is  if src and dest match) and hash by calculation of the local files hashes.
`Checks the files in the source and destination match. It compares sizes and hashes (MD5 or SHA1) and logs a report of files which don't match. It doesn't alter the source or destination.
If you supply the --one-way flag, it will only check that files in the source match the files in the destination, not the other way around. This means that extra files in the destination that are not in the source will not be detected.`

```
Transferred:             0 / 0 Bytes, -, 0 Bytes/s, ETA -
Checks:               179 / 179, 100%
Elapsed time:      4m18.0s

real    4m23.399s
user    1m30.188s
sys     0m28.248s
```