Server consolidation through virtualization is the primary strategy for optimizing data centres, aiming to maximize server efficiency and reduce costs. However, the long-term success of this strategy is compromised by three interconnected factors: virtualization overhead, the difficulty of modelling representative workloads with dependencies, and scalability limitations. This perspective article argues that scalability in consolidated environments is not a hardware problem, but rather a systems engineering problem, requiring a deep understanding of the interactions and constraints imposed by hypervisor overhead. More >