This feature is possible only on version 5.1 and above using the vSphere Web Client... you can read more about here: Enhanced vMotion with vSphere 5.1 - Eric Sloof - NTPRO.NL
With version 5;0 do you have two options:
1. shutdown the VM and make the migration changing the datastore and host simultaneously;
2. use a swing LUN (aka transfer LUN) and this way you can make the Storage vMotion and then the vMotion;
Some more about swing LUN: Say goodbye to the "Transfer LUN" aka "Swing LUN" aka "Stepping Stone&q…