High Quality Content by WIKIPEDIA articles! ktrace is a utility included with certain versions of BSD Unix and Mac OS X that traces kernel interaction with a program and dumps it to disk for debugging and analysis. It is somewhat similar to Linux`s strace, except much faster - with strace, every system call executed by the program being traced requires context switch to the tracing program and back, while with ktrace, tracing is actually performed by the kernel, so no additional context switches are required.