The VMware vMSC and SRDF/Metro environment that this design guide describes is a nonuniform configuration for vMSC with SRDF/Metro, meaning that ESXi hosts in each data center only see their respective PowerMax array. Because SRDF/Metro maintains the cache state on each array, an ESXi host in either data center detects the virtual device as local. Even when two VMs reside on the same data store but are located in different data centers, they write locally without any performance impact to either of them. Each host assesses and is served by its own array, with SRDF/Metro ensuring consistency.
For more information, see VMware vSphere Metro Storage Cluster Recommended Practices.