LUN alignment requirements for 5.1

When creating a new LUN, ESXi host and datastore in 5.1, what are the requirements for insuring proper LUN alignment?

• For example, if I create a new NFS mount in NetApp and create a datastore on it in VMware, should everything be aligned by default or are there any extra steps or checks I need to do to confirm that?

• If I create a new Fibre Channel LUN and create a datastore on it in VMware, should everything be aligned by default or are there any extra steps or checks I need to do to confirm that?  Any caviats or gotchas?

I'm not thinking about aligning the operating system with the virtual disk at this point, just with getting alignment from the datastore downward

Thanks!