One of VMware’s more interesting features is record/replay. This feature in VMware Workstation records everything that happens so that you can replay the recording at a later time. The recording offers 100 percent fidelity; every instruction that executed during the original recording is executed during a replay. Even if the recording includes a one-in-a-million race condition that you can’t replicate, it will be included in the replay.

VMware also has a movie-capture feature that records only the video output, but record/replay actually executes the CPU instructions of the OS and programs. And, unlike a movie, you can interrupt the execution at any point to interact with the computer and make changes in the virtual machine. For example, if you make a mistake in a program that lacks an undo feature, you can restore your virtual machine to the point prior to that mistake to do something different.

As we introduce more tools throughout this book, we’ll examine many more powerful ways to use record/replay. We’ll return to this feature in Chapter 8.