vizioncore published a short but good whitepaper aimed to help virtualization professional in migrating from VMware ESX Server 2.x to the new VMware Infrastructure 3, highlighting 10 major steps:
- Read all documentation thoroughly before you begin
- Identify each virtual machine and its associated host for migration
- Map interdependencies of virtual machines
- Create a schedule and workflow of virtual machines in required order
- Identify the method of migration
- Back-up your existing virtual machines and establish a fail-back strategy
- Always begin with a test virtual machine
- Perform migration steps in sequential order
- Manage your downtime window effectively
- Leverage automation whenever possible
While some points are really given for assured, others are good advices worth to read. Download it here.