| Modern computing has matured into a data-intensive, service-oriented activity, leading to increasing storage and I/O demands. However, current storage systems are built on slow, failure-prone, mechanical disks. These systems already face limitations of deployment scale, power consumption and performance. In order to meet current and future storage needs, systems need to incorporate new storage media.;NAND Flash is steadily maturing as a mass storage device, and Flash-based storage systems are a promising solution for the new demands of data-driven com- puting. Flash-based storage promises better performance than mechanical disks. However, existing system software is ill-suited to properly manage the performance characteristics of Flash-based storage. The combination of inappropriate system support and Flash characteristics can lead to the breakdown of service guaran- tees like fairness and performance isolation. On the other hand, in developing appropriate system support for Flash-based storage, the opportunity to develop mechanisms for additional, stronger service guarantees arises.;This dissertation approaches system support for Flash-based storage from two perspectives. First, understanding and managing Flash performance is necessary in order to provide reliable service to applications. In particular, an I/O scheduler based on Flash-oriented principles can provide better fairness and eciency than traditional I/O schedulers. Second, Flash-based storage provides unique charac- teristics and high performance that can enable more powerful I/O capabilities that a properly designed system can provide to users. Flash-based storage can eciently support a new I/O primitive, failure-atomic msync(), that allows ap- plication programmers to failure-atomically evolve durable application state in a straightforward manner. |
