Optimization and bottleneck analysis of network block I/O in commodity storage systems

Building commodity networked storage systems is an important architectural trend; Commodity servers hosting a moderate number of consumer-grade disks and interconnected with a high-performance network are an attractive option for improving storage system scalability and cost-efficiency. However, such systems incur significant overheads and are not able to deliver to applications the available throughput. We examine in detail the sources of overheads in such systems, using a working prototype to quantify the overheads associated with various parts of the I/O protocol. We optimize our base protocol to deal with small requests by batching them at the network level and without any I/O-specific knowledge. We also redesign our protocol stack to allow for asynchronous event processing, in-line, during send-path request processing. These techniques improve performance for a 8-disk SATA RAID0 array from 200 to 290 MBytes/s (45% improvement). Using a ramdisk, peak performance improves from 3...

• Type: Conference
• Year: 2007
• Where: ICS
• Authors: Manolis Marazakis, Vassilis Papaefstathiou, Angelos Bilas
• Keywords: Commodity Servers, Computer System, I/o Protocols, ICS 2007, Theoretical Computer Science