FlashFire: Overcoming the Performance Bottleneck of Flash Storage Technology

Flash memory based Solid State Drives (SSDs) are becoming popular in the market place as a possible low-end alternative to hard disk drives (HDDs). However, SSDs have different performance characteristics compared to traditional HDDs, and there has been less consideration for SSD technology at the Operating System (OS) level. Consequently, platforms using SSDs are often showing performance problems especially with low-end SSDs. In this paper, we first identify the inherent characteristics of SSD technology. Using this as the starting point, we propose solutions that are designed to leverage these characteristics and overcome the inherent performance problems of SSDs. At a macro-level, we propose a device driver-level solution called FlashFire that uses a Cluster Buffer and Smart Scheduling of read/write I/O requests from the OS. The net effect of this solution is to aggregate the small random writes from the OS into large sequential writes, and then sending them to the physical storage. We have implemented FlashFire in Windows XP and have conducted extensive experimental studies using disk benchmark programs as well as real workloads to validate its performance potential. We verified that FlashFire is able to provide better performance tuned to the intrinsic characteristics of SSD storages. For instance, the slowest netbook took 74 minutes to install MS Office 2007 package, and the time was reduced to 16 minutes with FlashFire. It is about 4.6 times better performance than before