Downloading an entire file is not practical for very large n-dimensional (n-d) datasets, especially if the region of interest (ROI) is small. It is therefore important to develop methods to allow researchers to remotely access n-d subsets of large datasets. Since researchers often wish to access a series of subsets, an awareness of the relationship between dataset storage organization and the application access pattern is important to guarantee effective performance. In our previous work, we reduced the impact of network latency costs even when efficient n-d access is available. This reduction in network latency costs exposes disk latency as an important performance factor. To address this new bottleneck and other problems, we propose the addition of n-d replicas to the data grid