Monitoring continues to be a challenge as IT teams move to the virtual environment. Elements of the IT infrastructure such as application availability and data center performance must therefore be monitored closely:
As workloads grow more complex and become virtualized or are moved to cloud environments, IT professionals can no longer measure infrastructure performance with gut instinct and basic tools. As a result, server performance monitoring tools must evolve to holistically monitor and analyze data center operation.
Check out the full post, Better Server Performance Monitoring Tools Needed with Virtualization, from SearchDataCenter.