Although flash storage has largely replaced hard disks in consumer class devices, enterprise workloads pose unique challenges that have slowed adoption of flash in ``performance tier'' storage appliances. In this paper, we describe Purity, the foundation of Pure Storage's Flash Arrays, the first all-flash enterprise storage system to support compression, deduplication, and high-availability.

As an emerging nonvolatile secondary storage technology, MEMS-based storage exhibits several desirable properties including high performance, high storage volumic density, low power consumption, low entry cost, and small form factor. However, MEMS-based storage provides a limited amount of storage per device and is likely to be more expensive than magnetic disk. Systems designers will therefore need to make trade-offs to achieve well-balanced designs. We present an architecture in which MEMS devices are organized into MEMS storage enclosures with online spares. Such enclosures are proven to be highly reliable storage building bricks with no maintenance during their economic lifetimes. We also demonstrate the effectiveness of using MEMS as another layer in the storage hierarchy, bridging the cost and performance gap between MEMS storage and disk. We show that using MEMS as a disk cache can significantly improve system performance and cost-performance ratio.

Non-volatile storage technologies such as flash memory, magnetic RAM (MRAM), and MEMS-based storage are emerging as serious alternatives to disk drives. Among these, MEMS storage is predicted to be the least expensive and highest density, and at about 1 ms access times still considerably faster than hard disk drives. Like the other emerging non-volatile storage technologies, it is highly suitable for small mobile devices but it is expensive to replace hard drives entirely. Its non-volatility, dense storage, and high performance still make it an ideal candidate for the secondary storage subsystem. We examine the use of MEMS storage in the storage hierarchy and show that using a technique called MEMS caching disk, we can achieve 30-49% of the pure MEMS storage performance by using only a small amount (3% of the disk capacity) of MEMS storage in conjunction with a standard hard drive. The resulting system is ideally suited for commercial packaging with a small MEMS device included as part of a standard disk controller or paired with a disk.