Missing Delete Logical Drive button ?

People,

I'm trying to reconfigure the Strip Size / Full Stripe Size of an existing LUNs, but somehow I've found something that is confusing.

In some of the Logical Drive I mark with the red, when you click on those two logical drives in the screenshot below, the Delete Logical Drive is missing ?



But when you click on the Logical Drive 3 as shown above, the delete button is there.

Does this also means when I need to change the Strip Size / Full Stripe Size of Logical Drive 1,2 and 3 I will need to delete all of them destroying all of the data ?

Any help would be greatly appreciated.

Thanks,