Past Event: Oden Institute Seminar

The Why and How of an All-Flash Enterprise Storage Array

Ganesh Ramanarayanan, Pure Storage

Abstract

The storage industry is currently in the midst of a flash revolution. Today's smartphones, cameras, USB drives, and even laptop computers all use flash storage. However, the $30 billion a year enterprise storage market is still dominated by spinning disk. Flash has large advantages in speed and power consumption, but its disadvantages (price, limited overwrites, large erase block size) have prevented it from being a drop-in replacement for disk in a storage array. The question facing the industry is how to build intelligent software that turns pools of flash into performant, reliable storage scaling to hundreds of TBs and beyond. In this talk, we describe the design of the Pure FlashArray, an enterprise storage array built from the ground up around consumer flash storage. The array and its software, Purity, play to the advantages of flash while minimizing the downsides. Purity performs all writes to flash in multiples of the erase block size, and it keeps its metadata in a key-value store that persists approximate answers, further reducing writes at the cost of extra (cheap) reads. Purity also reduces data stored on flash through a range of techniques, including compression, deduplication, and thin provisioning. The net result is a flash array that delivers a sustained read-write workload of over 100,000 4kb I/O requests per second while maintaining uniform sub-millisecond latency. With many customers seeing 4x or greater data reduction, the Pure FlashArray ends up being cheaper than disk as well. Bio: Ganesh Ramanarayanan is a Silicon Valley engineer / entrepreneur with broad interests in computer science and technology. He received his Ph.D. from Cornell University, specializing in visual fidelity and perceptual algorithms for computer graphics. After working on music search and query classification algorithms at Google, he co-founded Color Labs, a social-networking and photo-sharing startup that was sold to Apple in late 2012. He recently joined the team at Pure Storage to help drive the transition from disk to flash storage in the datacenter.