Deleting the mirror copy does not delete the LUN on disk - your 2nd copy of the data is safe.  Deleting any part of the mirror definition does not delete data - it will just break the relationship and stop copying.  Note, you may want to time when you delete your mirror copy so your application data in the copy is consistent - best to do it when the source host is either shut down or at least the application is quiesced, and the mirror sync has copied from that time - easiest way to tell is that the latest copy has brought over 0 bytes of data.
In EMC VNX mirror view if i delete the secondary image from the mirror view the secondary image LUN will be avaliable on storage array or it will be deleted permanently from the array ?
EMV VNX mirror view