Two ESX 3.x hosts mounting to same VMFS datastore on SAN

I'm running two ESX 3.x servers with virtual center. I know that it is possible to create redundancy or high availability by configuring a clustered environment. For HA to work, both ESX hosts must mount to the same datastore on SAN. When one ESX host goes down, the other ESX can take over the VM. How do I configure the second ESX 3.5 server to mount on to an existing VMFS datastore, but the primary ESX host must still maintain its master status? Could someone explain the configuration steps?

Thanks