Beating the I/O bottleneck: a case for log-structured file systems

• DOI: 10.1145/65762.65765
• Publication Date: 2004-10-12T15:03:40Z
• Authors: John Ousterhout; Fred Douglis
• Keywords: Disk buffer; Paging

CPU speeds are improving at a dramatic rate, while disk not. This technology shift suggests that many engineering and office applications may become so I/O-limited they cannot benefit from further improvements. paper discusses several techniques for I/O performance, including caches, battery-backed-up cache logging. We then examine in particular detail an approach called log-structured file systems , where the system's only representation on is form of append-only log. Log-structured potentially provide order-of-magnitude improvements write performance. When combined with arrays small disks (which high bandwidth) large main-memory caches satisfy most read accesses), we believe it will be possible to achieve 1000-fold performance over today's systems.