Jiri Schindler Graduate Student Department of Electrical and Computer Engineering Carnegie Mellon University Finger info

Research

Current

• Traxtents: Matching access patterns to disk characteristics

  Aligning disk accesses on track boundaries and modifying I/O sizes to match track size can significantly improve the performance of applications. Our Traxtent implementation in FreeBSD's FFS proved that the track-aligned access can be cleanly integrated to the system without exposing any disk-specific information.

• Freeblock scheduling

  To utilize available disk bandwidth that is otherwise wasted, we developed a freeblock scheduler. The scheduler identifies rotational latencies of primary workload requests and matches those to the suitable requests of a secondary (background) workload. Since background requests complete within the rotational latancies, they have zero impact on the performance of the foreground application.

• Automated Disk Characterization

  The goal of this project is to extract performance-critical parameters from a SCSI attached disk drive. The extracted parameters fall into four categories. Geometry and layout, mechanical overheads, cache characteristics and algorithms and command processing overheads. The extracted parameters can be utilized in aggressive disk-scheduling algorithms or fed directly to disk drive simulators e.g., DiskSim.

  The ideas have been put into DIXtrac, a program for automated extraction of disk paramters from SCSI disk drives. It is implemented on Linux and requires no special hardware.

  DIXtrac is not currently available, but we are preparing it for release to general public. In the meantime, check the database of validated disk specifications.

Previous

• WISARD

  WWW-based Interpretative System for Antibiotic Resistance Data ( WISARD) is a tool for collection and analysis of antibiotic resistance data. It offers detailed graphical and tabular analyses of data, comparisons of trends in two different entities (countries, hospitals, or medical wards) as well as an import tool for incorporating resistance data into the WISARD database.

• W3-EMRS

Publications

Eitan  Bachmat and Jiri Schindler. Analysis of Methods for Scheduling Low Priority Disk Drive Tasks. Appears in Proc. of ACM SIGMETRICS (Marina Del Rey, June 15-19, 2002),