DATE: Thursday, March 25, 2004
TIME: Noon - 1 pm
PLACE: Wean Hall 8220

Eno Thereska

A Framework for Implementing Unobtrusive Disk Maintenance Applications

This talk describes a programming model and system support for clean construction of disk maintenance applications. Such applications expose the disk activity to be done, and then process completed requests as they are reported. The system ensures that these applications make steady forward progress without competing for disk access with a system’s primary applications. It opportunistically completes maintenance requests by using disk idle time and free-block scheduling. Three disk maintenance applications (backup, write-back cache destaging, and disk layout reorganization) are adapted to the system support and evaluated on a FreeBSD implementation. All are shown to successfully execute in busy systems with minimal (e.g., <2%) impact on foreground disk performance. In fact, by modifying FreeBSD’s cache to write dirty blocks for free, the average read cache miss response time is decreased by 15–30%.

Eno Thereska is a second year graduate student at Carnegie Mellon's Parallel Data Lab working under Prof. Gregory Ganger. His research interests lie in self-managing storage systems. In particular, his current research focuses on Self-* (pronounced Self-star), a large constellation of autonomous storage bricks.

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