One of my clients has a Drobo 5D. Four of the five bays were filled 4 TB drives. I added a fifth drive (to the 0 slot), an 8TB drive. The Drobo seemed to recognize the drive and used it for additional capacity. I then pulled one of the 4 TB drives and swapped in another 8 TB drive. This time, instead of automatically seeing the extra space and using it, the Drobo asked me to create a new volume.
What do I do at this point so the Drobo adds the additional storage space to the current volume without destroying the volume and the data currently on it?