UniviStor: Integrated Hierarchical and Distributed Storage for HPC

High performance computing (HPC) architectures have been adding new layers of storage, such as burst buffers, to tolerate latency between memory and disk-based file systems. However, existing file system and burst buffer management software typically manage each storage layer separately. As a result, the burden of moving data across multiple layers falls upon HPC system users. To hide the complexity of managing the scattered storage devices from applications, we introduce UniviStor, a data management service offering a unified view of storage layers. By considering each layer's distinct characteristics, UniviStor provides performance optimizations and data structures tailored for distributed and hierarchical data placement, interference aware data movement scheduling, adaptive data striping, and lightweight workflow management. UniviStor supports parallel I/O library APIs, such as MPI-IO and HDF5. Our evaluations on a large-scale supercomputer demonstrated that UniviStor outperforms Data Elevator, a state-of-the-art transparent caching solution for burst buffers by up to 17x, and Lustre by up to 46x.