Lustre I/O performance investigations on Hazel Hen: experiments and heuristics

Abstract

With ever-increasing computational power, larger computational domains are employed and thus the data output grows as well. Writing this data to disk can become a significant part of runtime if done serially. Even if the output is done in parallel, e.g., via MPI I/O, there are many user-space parameters for tuning the performance. This paper focuses on the available parameters for the Lustre file system and the Cray MPICH implementation of MPI I/O. Experiments on the Cray XC40 Hazel Hen using a Cray Sonexion 2000 Lustre file system were conducted. In the experiments, the core count, the block size and the striping configuration were varied. Based on these parameters, heuristics for striping configuration in terms of core count and block size were determined, yielding up to a 32-fold improvement in write rate compared to the default. This corresponds to 85 GB/s of the peak bandwidth of 202.5 GB/s. The heuristics are shown to be applicable to a small test program as well as a complex application.

Providing High-Speed Data Access for Parallel Computing in the HPC Cluster

“…After that, the interaction between the client and the selected OSS is carried out directly through a high-performance data network. This solves the problem of the formation of "bottlenecks" in the access of computing nodes to a single data storage [8].…”

Distributed Computing Solutions for High Energy Physics Interactive Data Analysis

“…There is literature comparing different technologies according to established benchmark suites [147,148]. In some cases, current knowledge allows to extract the best performance of a given object storage tool, through fine-tuning of user space parameters [149]. This work does not attempt to modify or tune the storage backend; rather, it focuses on addressing analysis needs from the perspective of the data format and the layer that implements I/O of the data format to various backends.…”