Deleting indices with shadow replicas

Normally when we delete indicies, the actual data on disk is deleted as well. However, when we delete the indices that are using shadow replicas, the data is not actually being removed from disk. Is this on purpose?
We're running 1.7.1.

Hi Natefox,

I just tried reproducing this locally, and when I deleted the index it also deleted the data on disk in the shared path. Can you give me a listing of the files that are still around after deleting the index, and the steps you are taking when creating/deleting the index?

Sorry, I missed a vital step: if you close the index first and then delete it - the shadow copy still remains but if you do the same thing to a non-shadow copy index the data is actually deleted off disk.

Okay, I am able to reproduce this now, will continue the discussion in https://github.com/elastic/elasticsearch/issues/13297

Thanks!