A cool new feature of vSphere5 is the VMware VSA. It is pretty much a virtual appliance that makes local storage shared storage.
VMware has just released a VSA Deep Dive document a must read if you are considering this solution.
Some of the ESXi requirements for VSA is:
- Host must be installed with ESXi 5.0
- It must be a greenfield deployment. No existing virtual machines running
- ESXi and vCenter server must have the same gateway address. They need to be on the same subnet
- 4 – 6 or 8 spindles is supported
Check out the document to find other requirements.