Recent development work at the Laboratory for Computational Science & Engineering (LCSE) at the University of Minnesota aimed at increasing the performance of parallel volume rendering of large fluid dynamics simulation data is reported. The goal of the work is interactive visual exploration of data sets that are up to two terabytes in size. A key system design feature in accelerating the rendering performance from such large data sets is replication of the data set on directly attached parallel disk systems at each rendering node. Adaptation of this system for interactive steering and visualization of fluid flow simulations as they run on remote supercomputer systems introduces special additional challenges which will briefly be described.