FIOS: a fair, efficient flash I/O scheduler
نویسندگان
چکیده
Flash-based solid-state drives (SSDs) have the potential to eliminate the I/O bottlenecks in data-intensive applications. However, the large performance discrepancy between Flash reads and writes introduces challenges for fair resource usage. Further, existing fair queueing and quanta-based I/O schedulers poorly manage the I/O anticipation for Flash I/O fairness and efficiency. Some also suppress the I/O parallelism which causes substantial performance degradation on Flash. This paper develops FIOS, a new Flash I/O scheduler that attains fairness and high efficiency at the same time. FIOS employs a fair I/O timeslice management with mechanisms for read preference, parallelism, and fairness-oriented I/O anticipation. Evaluation demonstrates that FIOS achieves substantially better fairness and efficiency compared to the Linux CFQ scheduler, the SFQ(D) fair queueing scheduler, and the Argon quanta-based scheduler on several Flash-based storage devices (including a CompactFlash card in a low-power wimpy node). In particular, FIOS reduces the worst-case slowdown by a factor of 2.3 or more when the read-only SPECweb workload runs together with the write-intensive TPC-C.
منابع مشابه
FlashFQ: A Fair Queueing I/O Scheduler for Flash-Based SSDs
On Flash-based solid-state disks (SSDs), different I/O operations (reads vs. writes, operations of different sizes) incur substantially different resource usage. This presents challenges for fair resource management in multi-programmed computer systems and multi-tenant cloud systems. Existing timeslice-based I/O schedulers achieve fairness at the cost of poor responsiveness, particularly when a...
متن کاملOn Disk I/O Scheduling in Virtual Machines
Disk I/O schedulers are an essential part of most modern operating systems, with objectives such as improving disk utilization, and achieving better application performance and performance isolation. Current scheduler designs for OSs are based heavily on assumptions made about the latency characteristics of the underlying disk technology like electromechanical disks, flash storage, etc. In virt...
متن کاملA New I/O Scheduler for Solid State Devices
Since the emergence of solid state devices onto the storage scene, improvements in capacity and price have brought them to the point where they are becoming a viable alternative to traditional magnetic storage for some applications. Current file system and device level I/O scheduler design is optimized for rotational magnetic hard disk drives. Since solid state devices have drastically differen...
متن کاملDeadline Fair Scheduling: Bridging the Theory and Practice of Proportionate Fair Scheduling in Multiprocessor Systems
In this paper, we present Deadline Fair Scheduling (DFS), a proportionate-fair CPU scheduling algorithm for multiprocessor servers. A particular focus of our work is to investigate practical issues in instantiating proportionatefair (P-fair) schedulers into conventional operating systems. We show via a simulation study that characteristics of conventional operating systems such as the asynchron...
متن کامل