In the Shared LUN FAQ there is this question:
Can a Shared LUN be used with external devices?
A Shared LUN can only be used with virtual drives within the chassis.
I presume that this applies to the vTrak DAS device connected directly to the SCM? This seems like a pretty significant shortcoming of the entire IMS SAN if the shared LUN capability cannot be utilized in that extended storage, so I would like to get a definitive answer on this.