There’s a lot to consider when you decide to upgrade previous versions of ESX to vSphere 5. Take some time to read the following PDF “vSphere 5 pricing and packaging white paper”
Other links to read:
- Upgrading to VMware vSphere License Keys
- How to Get Your vSphere 5 Licenses
- Upgrade Eligibility
- Entitlement Mapping
- Preparing for Your License Upgrade
- Version Downgrade
- vSphere Licensing Roles
- Further Licensing Questions