[Sesse__]

> On a hard disk, copying multiple files in parallel is likely to make the copy run slower because it spends more time seeking back and forth between the files (except for small files).

Certainly not; it's likely to make it run faster, since you can use the elevator algorithm more efficiently instead of seeking back and forth between the files. You can easily measure this yourself by using comparing wcp, which uses io_uring, and GNU cp (remember to empty the cache between each run).

[kragen]

Hmm, that's interesting! I don't have a hard disk handy right now, unfortunately.