Thursday, March 25, 2004
Noon - 1 pm
Wean Hall 8220
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 systems 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 FreeBSDs
cache to write dirty blocks for free, the average read cache miss response
time is decreased by 1530%.
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
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