Mac OS X 10.5: Using DTrace instead of KTrace
The command line-based process debugging tool KTrace, which is used for tracing kernel processes in Mac OS X 10.4 and earlier, is not included with Mac OS X 10.5 Leopard. There is no manual entry (man) for the command line-based process debugging tool KTrace.
Mac OS X 10.5 or later utilizes a more robust kernel tool called DTrace.
You can learn more about DTrace and its usage by opening Terminal and typing: man dtrace