The new Zimbra Wiki article linked below will be of particular interest to Zimbra Partners deploying ZCS in a virtualized manner in a customers' data center, or in the partners' own hosted environment.

The article includes a short list of essential best practices and recommendations to ensure a high performing Zimbra deployment on the VMware's vSphere virtualization platform. Also we’ve provided a list of recommended reference material to build and deploy a vSphere virtualization platform with performance in mind, as well as troubleshooting steps to resolve performance-related issues.

Performance Recommendations for Virtualizing Zimbra with VMware vSphere 4 - Zimbra :: Wiki

Andy Pflaum
Zimbra Global Channels & Business Development