Interesting set of articles on the Amazing VM Record/Replay Feature in VMware Workstation 6.  Steve Herrod, VP of Engineering at VMware, describes the challenge of recording and replaying the execution of a virtual machine.  At first it may seem straightforward – we all know what record / replay is – but it gets complex given the need to replay the exact timing of external interrupts to the operating system and other non-deterministic behavior. For replay to work, there is a lot of data to record.

And there are some useful implications for software development and debugging.

For those wanting even more detail, one of the development engineers on this feature describes additional technical nuggets.