SATA multi-actuator drives appear as a single drive to the system stack, yet all IO is addressed to LBA ranges on each actuator. Linux IO schedulers must be aware of this geometry via log pages in ATA Command Set –5 and then optimize behavior to ensure that actuators are kept busy. Legacy IO scheduler behavior can lead to underutilized actuators, delayed IO completion resulting in poor performance. Paolo Valente Assistant Professor of Computer Science at the University of Modena and Reggio Emilia, Italy in consultation with Seagate Technology has developed a version of the BFQ IO scheduler that is optimized for multi-actuator drives demonstrating dramatic performance improvements over a wide range of workloads. The concepts and strategies used by BFQ can inform changes to IO schedulers, the Linux kernel, and storage applications to take advantages of the IOPS gains of multi-actuator drives. Dual LUN SAS dual actuator drives are in market today with SATA and Single-LUN SAS drives coming as the need for maintaining IOPS becomes increasingly important as drive capacities grow.
- Understand legacy Linux storage stacks performance in relation to SATA and Single LUN multi-actuator Drives
- Learn how the BFQ scheduler is optimized to provide optimal performance on dual actuator SATA drives
- Create strategies for updating Linux storage stacks and storage systems for SATA and Single LUN SAS multi-actuator drives
- Use of performance tools and scripts in measuring multi-actuator performance