If the LUN with the first VMDK file does not have a 8 MB block and you have issues snaphotting the large 2 TB vmdk file, you can repoint the working directory to where you want the snapshot to be created. You need to edit the vmx file of the VM. This will allow you to have the snapshots create on a LUN of your choice and not nessissarily the LUN that has the OS vmdk file.
change the line below in tghe VM .vmx file to the path of the datastore you want the snapshot file created in.
WorkingDir="<new_path_location>"
after you will need to unregister and then bring the VM back into inventory for the ESX to accept this change.
Ernie