Jason Alexander Smith (Brookhaven National Laboratory (US))
Solid state drives (SSDs) provide significant improvements in random I/O performance over traditional rotating SATA and SAS drives. While the cost of SSDs has been steadily declining over the past few years, high density SSDs continue to remain prohibitively expensive when compared to traditional drives. Currently, 1TB SSDs generally cost more than USD $1,000, while 1TB SATA drives typically retail for under USD $100. With ever-increasing x86_64 server CPU core counts, and therefore job slot counts, local scratch space density and random I/O performance have become even more important for HEP/NP applications. FlashCache and Bcache are Linux kernel modules which implement caching of SATA/SAS hard drive data on SSDs, effectively allowing one to create hybrid SSD drives using software. In this presentation, we discuss our experience with FlashCache and Bcache, and the effects of this software on local scratch storage performance.
Christopher Hollowell (Brookhaven National Laboratory)