Upstarts may have pioneered the use of flash memory in enterprise storage arrays, but the incumbents are in an excellent position to exploit the technology with updated architectures.
Established storage vendors, including HDS, EMC, and IBM, have all recently made significant investments in flash technology, either through internal development or through acquisition. Last year, HDS announced it had developed its own flash storage module for its Virtual Storage Platform, claiming it would deliver better performance, energy efficiency, and capacity and lower costs per bit. EMC, meanwhile, snapped up flash memory startup XtremeIO and has also redesigned its VNX product line with flash. A year after acquiring veteran PCIe-based solid-state disk maker Texas Memory, IBM laid out its roadmap for flash, which includes developing a controller for its storage arrays that are optimized for use with Toshiba’s NAND chips.
Mark Peters, senior analyst with Enterprise Strategy Group (ESG), says it’s important to remember that flash memory in enterprise storage is not a market -- it’s a technology that is being incorporated into storage arrays in a variety of ways.
Some vendors, whether they are established storage providers or younger independents, are taking an all-flash approach, while others have hybrid architectures. For example, Nimble Storage’s Cache Accelerated Sequential Layout (CASL) architecture combines the performance of flash memory and low-cost disk capacity. CASL takes random writes coming into the system and writes them on a new location on disk sequentially, making more efficient use of low-cost disk. Frequently requested data sits on the flash layer but also resides on disk.
Tiering data based on how often it is accessed and placing it on faster flash memory, rather than spinning disk, is a popular approach to leveraging the technology. But, as I reported last week, Violin is using flash for what Narayan Venkat, Violin VP of products, describes as the most economical persistent memory, thereby optimizing applications for better performance.
Moving the smaller application rather than a large volume of data makes more sense, observes Jim Handy, principal analyst at Objective Analysis: Why move the mountain to Muhammad when you can move Muhammad to the mountain?
Of the many independents, Violin, Nimble, and Fusion-io have been the most successful to date, says ESG’s Peters, noting Fusion-io has expanded its capabilities since its inception, in part due to its recent acquisition of hybrid storage appliance startup NextGen, which already used Fusion-io flash cards in its n5 arrays.
A particularly notable acquisition is Cisco’s recent purchase of all-solid-state array vendor Whiptail. As Network Computing’s Howard Marks noted in his blog, Cisco was the only name-brand server vendor without a storage division, having certified reference architectures with storage vendors that include startups and larger vendors such as EMC and NetApp.
In addition to the acquisition activity, there’s been plenty of investment in the flash memory space as well. Violin recently went public, Nimble has filed for IPO, and all-flash enterprise storage company Pure Storage recently raised $150 million in pre-IPO VC funding. Dell, having bolstered its enterprise storage business with the acquisition of Force10 in 2011, led a round of $51.6 million funding for flash storage startup Skyera. Dell also recently began shipping its own Compellent storage system, which auto-tiers data between high-speed SLC flash memory with slower but lower-cost MLC flash memory.
With all of this flurry of activity, it’s still not clear what the best architecture might be for incorporating flash into enterprise storage architectures. IBM, for example, sees a number of different deployment models for flash storage, including direct-attached, solid-state drives that plug into serial ATA and serial-attached SCSI interfaces for hard drives and PCI Express slots. It also projects flash in DIMM slots seeing more uptake in 2014.