-Dlogfile=sys:zenworks\zenwsimp.log provides the path and file name that will be used for logging messages to a file.
-Dlogfilelevel=2 pertains to logging to a file on the server (the file specified in the first switch above). It can range from 0 to 3, where 0 does not log anything and 3 is the most verbose of the message sets.
-Dloglevel=0 pertains to logging to the server console. Like the first switch, it can also range from 0 to 3, where 0 does not log anything and 3 is the most verbose of the message sets.
-ns works in conjunction with the third switch above. When -ns is not included, all messages go to the main console screen of NetWare, which is usually not a desirable place for debugging messages to go. When this switch is included, the debugging messages will go to their own screen. (Access the screen through Ctrl+Esc or Alt+Esc.)