A machine implemented method includes creating a universally unique identifier, detecting a trigger of a sleep event, and associating the universally unique identifier with the sleep event. The method monitors sub-system events that occur after a sleep event has been triggered and stores data in non-volatile non-disk storage (e.g., non-boot storage) identifying an event stage corresponding to the sub-system event that is occurring. The method determines whether a wake event has completed and logs each of the sub-system events using the universally unique identifier until a wake event has completed.