All-Flash Data Centers: Quick as Lightning

Like the thunderbolt-sporting superhero, flash memory is quick, flash memory is quick. With no moving parts, flash resembles primary memory more so than secondary disk storage when it comes to saving and reading data.

As the cost of flash declines, data center managers are seeing flash as an attractive alternative to traditional hard-disk methods. By some estimates, flash memory prices have fallen at an average of 35% per year over the last few years.   

The Next Generation of Data Centers

The consumerization of IT, coupled with online services like social media, creates a need for flexibility and performance improvements within current data centers without the associated costs.

Disk storage was revolutionary in its ability to cost-effectively store larger quantities of data compared to the then-outgoing storage medium: tape. Despite the introduction of flash, spinning disks persisted as the de facto server architecture. Why?  Regardless of flash’s significant performance benefits, it was simply too expensive to consider as a full-fledged alternative to spinning disks. Additionally, for the price, flash was relatively smaller in capacity and incapable of retaining comparable levels of data with respect to spinning disks.

However, recent developments in flash have chipped away at its shortcoming: flash is now quite reasonable in price. As the cost of flash has fallen, its primary benefits – speed in throughput and latency – have dramatically increased concurrently. Furthermore, flash outperforms hard disks and consumes a small fraction of the electricity, sometimes at the ratio of one to 16. And despite relative durability shortfalls, recent improvements have made flash an increasingly feasible – and desirable – option, even in high-volume environments such as the data center.

The All-New Data Center, Flash Included

The modern data center resembles an alpha city: skyscrapers of networking equipment line the narrow passageways between each block of appliances; ethernet cords are strung throughout the center much like the electric cabling powering city buses. Towers of storage capacity fill the room; surely they couldn’t all be running on flash storage?

Today, those data centers could very well be all flash. Tomorrow, it’s certain that they will. For major industries whose profit margins depend on the availability and speed they can offer their customers, flash storage’s undeniable performance is becoming less of a temptation and more of a business necessity. File hosting services, like Amazon’s Simple Storage Service (S3) or Dropbox, handle requests in the realm of 650,000 per second. Telcos and service providers – whose business models are extremely sensitive to latency and downtime – are particularly interested in an all-flash data center model.

Consider the drastic differences between hard-disk drives (HDDs) and solid-state drives (SSDs). A state-of-the-art HDD spinning at a maximum 15,000 revolutions per minute – beyond which the hardware has a high probability of failure – achieves anywhere between 180 and 200 input/output operations per second (IOPS). While the technology has proven sufficient in the past, today’s data storage requirements are now being challenged to go even faster. Performance achievable from flash storage supersedes even the best HDDs on the market. Solid-state drives offer between 3,000 and 3,500 IOPS per unit, netting a performance benefit of over 94 percent. The use-case for flash has never been more attractive both from the price standpoint as well as performance benefits.

Despite the appeal of an all-flash data center model, other industries continue to hold off on adoption until the cost of flash drops further. Today, the tradeoff is between price and capacity. But when the price of flash catches up to the price of spinning disks, there will suddenly be no reason for choosing the latter. Just as spinning disks replaced tape storage with its better value proposition, so too will the market shift towards adopting flash as the preferred storage medium.

Software-Defined Storage and the All-Flash Data Center

Software-defined storage is another storage trend gaining comparable traction to flash. While it might be too soon to call the two trends linked, it is indisputable that a software-defined approach to storage infrastructure presents organizations the required flexibility to seamlessly adopt an all-flash data center strategy.

Software-defined storage works by migrating features typically found in hardware to the software layer. The virtualization of hardware operations means IT managers can do away with built-in and inefficient redundancies found within the hardware layer. No matter the vendor, cost or technology, hardware inevitably fails. Flash storage, in particular, currently has a quicker time-to-failure rate than spinning disk options. In traditional storage setups without RAID cards, the failure of a disk typically prompts an error that will impact the end-user’s experience. The error is typically resolved by using RAID cards to hide the errors, which can be costly. With the right software-defined approach, these problems would be concealed, allowing users to continue unabated. Furthermore, software-defined storage is hardware-agnostic and can operate on any hardware setup.

By adopting a software-defined approach to storage architecture, the organization could still utilize a single name space spanning all its storage nodes. Organizations could also run applications in the storage nodes, turning them into “compustorage” nodes. As a result, the storage hardware itself would not need to be large or expensive, but would still retain high levels of performance and speed. Therefore, rather than building a large, expensive and traditional installation, organizations can start with a small number of cheap servers, and if needed, scale linearly from there and be left with a cost-effective, high-performance data center.

Four Immediate Benefits of an All Flash Data Center

Other benefits of an all-flash data center running software-defined storage technology include:

  1. Substantial performance improvement through the ability to use the faster flash technology throughout the data center
  2. Operating more applications on the same hardware, due to hardware performance gains
  3. SSDs have a smaller footprint in the data center. Since SSDs are physically smaller than spinning disks, they require less real estate to house them.
  4. Reducing power consumption means that SSDs reduce operating costs by generating less heat than a spinning disk and requiring less energy for cooling.

Moving Forward

Our superhero Flash can run as fast as the speed of light and today’s data is no different. The technology to capture and store this information is always changing. It was not long ago when spinning disks were novel in design and capability. The introduction of HDDs phased out tape storage and presented new possibilities for innovation in computing as a whole. Now the time has come for flash to take the helm as the industry norm with its unmatched performance, low energy usage and rapidly declining cost. The data center of tomorrow is right around the corner: coupling an all-flash architecture with a software-defined strategy beckons the next wave of storage.

About the Author:

Stefan Bernbo is the founder and CEO of Compuverde. For 20 years, Bernbo has designed and built numerous enterprise scale data storage solutions designed to be cost effective for storing huge data sets. From 2004 to 2010 Stefan worked within this field for Storegate, the wide-reaching Internet based storage solution for consumer and business markets, with the highest possible availability and scalability requirements. Previously, Bernbo worked with system and software architecture on several projects with Swedish giant Ericsson, the world-leading provider of telecommunications equipment and services to mobile and fixed network operators.