Data stores per LUN

Hi,

Im just reconfiguring our SAN, and have setup one large array as a single LUN to ESXi 4.1.

I was under the impression that i could have multiple datastores on one LUN, with each host accessing a different datastore on that LUN?

Can somoene confirm?

Or will i have to carve the array up SAN side, and assign a chunk for each datastore i want, on a different LUN?

Thanks in advance all.