I followed the link above and read Duncan's post. One thing that's changing quickly is the use of VAAI. If you have a VAAI-capable storage array that supports the ATS primitive, you have less to worry about with regards to too many hosts accessing a particular datastore at one time.
I don't have much in the way of warnings about performance or other limitations.
How do you break up your vSphere clusters? Maybe the same logic can hold for your storage. This is especially true if your clusters are geographically dispersed. You don't want a VM running on a host n Miami with its VMDKs in San Jose. I wouldn't even want this configuration if it were across town.
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Mike Brown
VMware, Cisco Data Center, and NetApp dude
Consulting Engineer
Twitter: @VirtuallyMikeB
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