There appears to be a bug in OS X Windows Sharing (e.g. Samba) in some of the latest releases. The Netbios name server daemon (nmbd) is activated, even when name serving is not enabled. It crashes and is respawned continously, driving up utilization.
Another symptom is that the log file /var/log/samba/log.nmbd continuously grows and becomes huge (GIGS!)
A fix is to turn off Windows Sharing, and delete that logfile. If you want to run Windows Sharing, copy the properties file /System/Library/LaunchDaemons/nmbd.plist to another location, while WIndows Sharing is off. Turn it back on, then copy this file back to its location. This will set the boolean 'Disabled' flag to 'Yes' - you could also use the Properties editor to add this.
Note that the copying is best done from the terminal using cp with sudo.
Reboot, and you have Windows Sharing without the problem. This fix will be gone, the moment you toggle Windows Filesharing in the Prefs pane. This means that the fix does not interfere with future updates.
Last edited: Jun 10, 2006