Thanks!
It's MPD v21. And he got a huge collection, yet he has let it to update the database for a day or 2 but just stuck at 11039th files. He said there should be many more files inside that folders (he used to play Voyage MPD before).
And there is nothing to show in "tail -f /tmp/stdout" nor "tail -f /tmp/stderr", please help. Or he has to return to Voyage MPD. Please help, sir. Or do u need the diagnostic file?