There's a lot to like about solid-state storage technology; it's small, runs cool, is power efficient and it's lightning fast. Put it head-to-head with traditional spinning media and it wins on nearly all counts, with admittedly some not-yet-fully resolved issues related to long-term reliability and price. Still, few would question that solid-state storage is the direction that enterprise storage is headed.
The real question is just how soon the transition from mechanical storage to solid-state storage technology will take place.
Although new to the data center, NAND flash-based solid-state storage has been around for a long time, used mostly in consumer and mobile products like smart phones, PDAs and MP3 players. The transition to data center-quality storage products involves more than just a matter of scale as the technology employed in mobile products isn't durable enough to stand up to the rigors of enterprise computing environments. But even at this early stage in its development, solid-state storage does have something of a track record in enterprise environments -- demonstrated perhaps most notably by Texas Memory Systems, which has been marketing DRAM-based storage arrays for more than decade. In recent years, the company has also added flash-based systems to its roster.
But NAND flash has been criticized as being too unreliable for enterprise-class storage. It can handle a limited number of writes before it simply wears out, and its write performance lags its read performance considerably. Those issues, however, are being actively addressed by scores of solid-state chip makers and integrators with novel approaches that yield reliability and performance improvements. Already, an impressive array of new NAND flash products is available -- products that clearly exceed the performance of hard disks and match their reliability as well.
The other criticism of NAND flash storage -- and the one expressed most frequently -- is that it just costs too much. If you compare NAND with hard disk storage on a dollar-per-gigabyte basis, the cost critics win the argument hands down. But that kind of comparison takes both types of storage out of context and also evades the many positive attributes of solid-state storage technology. Proponents of solid state say that the only valid means of comparison is on a performance-per-dollar basis. That argument is simple and very convincing. For example, a high-performance application may require dozens of high-speed disks and use only the outer parts of those disks to ensure quick response times. So, a lot of relatively expensive high-speed disks will be used to only partially satisfy the app's needs. A solid-state alternative would require far fewer units and all the capacity on each would be available to the application, and it has an inherent speed advantage from the get go. So which costs more, a lot of pricey spinning disks or a handful of NAND flash drives?
And even if the price were equal, solid state provides enormous advantages over spinning disk in power consumption, heat production and footprint. In some shops, those savings alone are enough to justify the move to solid state. The goal for any data storage manager is to have storage systems that are reliable, provide sufficient performance, can be easily maintained and are cost effective.
--Rich Castagna, Editorial Director of the Storage Media Group
TABLE OF CONTENTS: ESSENTIAL GUIDE TO SOLID-STATE DRIVES
♦ SSD trends in enterprise storage
Solid-state storage technology, or solid-state drive (SSD) technology, is nothing new, but it wasn't even considered for enterprise storage until recently because the current cost of SSDs is still high. In addition, SSDs can present many challenges if not implemented correctly. But compared to Fibre Channel (FC), solid-state storage technology offers a big performance boost, and you can choose between two types of SSD technology for your data storage: DRAM SSD and NAND flash. But even with the performance boost benefits, will solid state be prominent in enterprise storage systems in the future?
♦ Wide stripe before you dive into SSD
If you have a high-performance application that requires a mix of read and write IOPS, your first thought might be to consider investing in solid-state storage technology to help improve your performance. But before you jump on the SSD bandwagon, consider other options available to you such as wide striping. Combining wide striping, internal virtualization and SSD technology can give you a wide array of performance benefits.
♦ Gamer's DRAM SSD leaves Fibre Channel in the dust
An Iceland-based online game producer switched from Fibre Channel to solid-state storage technology because its core product started showing signs of game lag due to stress from its database and storage array. The firm uses DRAM-based SSD technology from Texas Memory Systems to handle its capacity needs.
♦ Low-cost MLC NAND flash gains in enterprise solid-state storage
In the past, most people assumed that multi-level cell (MLC) NAND flash was only fit for consumer devices, and single-level cell (SLC) flash SSDs were best suited for enterprise applications. However, a new class of MLC NAND flash is coming on the market that might make its way into the enterprise. Will it replace SLC flash?
♦ Channel perspective: When to recommend SSD
Customers interested in solid-state storage technology have a lot to consider. Should they go with a traditional storage supplier or a legacy SSD supplier? Should they choose flash SSD technology or DRAM-based SSD? Before pointing a customer in one direction, be sure you first understand what they need SSD for and that they aren't trying to move their entire data set to SSD. Solid-state storage is more suited for specific files or subsets that could improve performance by being place on solid-state drives.