Essential guide to hybrid flash arrays
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Now that most enterprises either have performance-boosting flash storage or plan to add it soon, the more interesting questions to explore are where and how flash usage will occur.
The ServInt Corp., a managed hosting provider with data centers in the U.S. and Europe, turned to a SolidFire all-flash system to offer its customers performance guarantees and to help eliminate "the noisy neighbor problem" of disk-resource contention, said Kevin Nicastro, vice president of innovation and technology at the Reston, Va.-based company.
Another early adopter, the Friedrich Miescher Institute for Biomedical Research, purchased an all-flash array from Whiptail (since acquired by Cisco) to speed the creation of virtual machines (VMs) with its OpenStack VM store, and to improve boot time, according to Dean Flanders, head of IT at the Basel, Switzerland-based institution.
EMC said it shipped 17 PB of flash in the first quarter of this year, with more than 70% of its VMAX and VNX2 enterprise arrays shipping with flash in them. NetApp said it has shipped 75 PB of flash storage since it began offering flash in its arrays, with all-flash arrays responsible for about one-third of that total.
Framingham, Mass.-based International Data Corp.'s most recent survey data showed three main enterprise deployment locations: storage arrays, host servers and flash appliances. The selection generally depends on the performance problem the user is trying to solve, according to Eric Burgener, a research director of storage at IDC.
Burgener said flash usage is high in virtual server and virtual desktop infrastructure (VDI) environments. Of the two, VDI tends to see the greater level of adoption, often to address the boot storms that happen when users log in at the same time.
IDC's mid-2013 survey of 307 enterprises with at least 1,000 employees and spanning a wide range of industries showed that 51.5% used some flash storage in their external disk storage environment. Nearly two-thirds of those enterprises added SSDs to their existing HDD arrays -- either as cache (37.3%) or as a flash storage tier (23.4%).
Burgener said users often deploy a small number of flash drives in an existing array because that is the easiest way to try out the technology. He said host-based deployments are another relatively simple option. The IDC survey showed that 12% used PCIe-based flash in servers.
IDC's survey showed that 18.4% used new hybrid arrays, and another 7% deployed all-flash arrays. One of the inhibiting factors for all-flash arrays has been their capacity limitations of less than 100 TB in many cases, limiting their use to one or two specific applications, Burgener said.
Burgener said when more all-flash array vendors support capacities approaching 1 PB, the products will become more viable options to replace enterprise storage workhorses, such as EMC's VMAX or IBM's DS8000.
With double-digit compound annual growth rate, IDC predicted flash-infused arrays will eventually supplant legacy storage architecture products. Hybrid arrays will be an $8.3 billion market this year and grow to $12.3 billion in 2016, and all-flash arrays will hit $800 million this year and increase to $1.6 billion in 2016, according to Burgener.
Tim Stammers, a senior analyst at New York-based 451 Research LLC, said cost remains an issue with all-flash arrays, but as flash prices drop, the case for an all-flash array may become more justifiable, especially for databases, VDI, server virtualization and analytics. He said that enterprises -- when doing comparison calculations -- need to consider the actual cost of trying to tune or short-stroke a disk-based or hybrid array to achieve sufficient performance against the certainty that an all-flash array can make the performance problem go away.
In 451 Research's most recent survey of IT professionals of midsized and large organizations, hybrid arrays were the most popular flash storage option followed by server-side flash.
Stammers noted that more respondents have long-term plans to implement hybrid arrays than server-side flash. But, the 451 Research survey also showed that spending on server-side flash is sharply rising among organizations that already use it or have plans to do so.
No matter how much flash gets deployed in performance-hungry scenarios, there will also continue to be demand for cheaper HDDs, according to Marco Coulter, a vice president and research director in storage for 451 Research's TheInfoPro.
Coulter said the hybrid array is the de facto storage architecture for flash in the enterprise. The main use case he hears about for an all-flash array is a VDI implementation that choked the performance of a traditional HDD-based array.
"It ran screamingly well, and they had some spare capacity left, so they moved Exchange [Server email] over as their next application to run off that all-flash array," Coulter said. "But, even in that scenario, it wasn't like they were saying, 'OK, now I'm going to replace all of my regular enterprise arrays with all-flash arrays.' They have a couple of apps. They buy a couple of all-flash arrays. That's where it's at right now."