The Yin and Yang of Memory Overcommitment in Virtualization
Yin & Yang is an ancient Chinese belief about the existence of two complementary forces in the universe - Yang represents everything positive or "Bright" and Yin stands for the opposite or everything negative or "Dark." Everything has both Yin and Yang aspects and the authors can't ignore one or the other. The authors see the same Yin & Yang effects in virtualization. For example, the authors can look at consolidation ratios; the higher the consolidation ratios, the better the server utilization, reduced power consumption and hence fewer physical servers to manage. On the other hand, the indiscriminate quest for higher consolidation ratios can cause performance problems and worse, such as increasing the business risks due to hardware failure.