I find a problem about the initialization of smbd with CUPS. If the port 631 is already used by a daemon(except cupsd), the smbd stops in the initialization. main() -> reload_service() -> reload_printers() -> pcap_cache_reload() -> cups_cache_reload() -> httpConnect() -> cupsDoRequest() -> recv() <--- STOP If the port 631 is already used by another daemon, httpConnect() succeeds. And the recv() is executed in cupsDoRequest(). As a result, the smbd waits some responses forever.
What are you running on port 631? The current behavior is by design. I don't see any timeout mechanism in the cupsDoRequest() call. You will need to file an issue with the cups developers.
I disabled the cups service. And the NFS(rpc.rquotad) used the 631 port which is assigned by portmap by chance. It caused our problem. I filed this issue to CUPS's bugs. http://www.cups.org/str.php?L1535+P0+S-2+C0+I0+E0+Q Thanks
Port 631 is a "well-known port" reserved for use by IPP servers only. Your NFS(rpc.rquotad) shows "illegal" behaviour in occupying that port