With LUN Affinity DISABLED, the Apple Disk Utility will show multiple drives for each Logical Unit (LUN) created.  The optimal configuration for use in the Mac OS X environment is to have LUN Affinity ENABLED. 

Optimal configuration, including setting of LUN Affinity can be found in the article: 10074 - Configuring VTrak for optimal performance in an Apple/Mac environment.  A link to this article can be found below.