What does the first phase of implementing security in virtualized data centers consist of?

Consolidating servers across different trust levels is a poor security practice as it mixes sensitive and less sensitive environments, increasing the attack surface.

In the initial phase of securing virtualized data centers, it's critical to consolidate servers within their respective trust levels to maintain isolation and prevent security compromise across different security domains.

Selectively virtualizing network security functions is typically a subsequent step, optimizing security controls after initial host and VM consolidation.

Implementing a dynamic computing fabric is an advanced architectural goal for elasticity and automation, not the foundational first security step in virtualization.