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The advent of the cloud has made it possible to virtualize many workloads, including desktops. But now IT pros are clamoring for faster networked storage.
All-flash arrays are the Ferraris of the storage world. They deliver high-quality performance and are poised to revolutionize the storage game by eliminating the need for spinning hard disk drives.
Networked storage faces a litany of challenges. When a user boots his virtual desktop, networked storage has to deliver the OS stack and applications the instance needs. Ideally, this happens immediately, but so many instance creations occur in batches -- especially in virtual desktop environments -- it sometimes feels like booting from a floppy disk.
How all-flash array storage can help
All-flash arrays can weather boot storms and solve many other virtualization performance problems. Although the appliances are expensive, they deliver the best performance for the price on a dollar-per-IOPS basis. The storage arrays are available in many different sizes. A mid-sized one can store a large configuration of desktop images, and it lets IT boot thousands of VDI instances per hour at a speed almost as fast as local storage.
The proliferation of large-capacity units creates another potentially sizable use case for all-flash array storage: as a top-tier network store for big data. In-memory database engines and GPU-based systems are I/O hogs that can quickly choke performance if the networked I/O system is too slow. A petabyte-scale all-flash-array or two can provide the bulk capacity big data needs, and they deliver it at high speed. Petabyte arrays are also affordable because they offer background deduplication, and the raw cost of capacity is less than $2 per GB.
Price points for all-flash array storage continue to improve, too. The rise of 3D NAND flash will drive the price of a gigabyte down even more in the next year, which widens the gap between the metrics of all-flash arrays and older spinning disk arrays. It would be reasonable to expect the technology to just keep improving.
Containers save the day
That being said, a new way of thinking about virtualization is poised to sweep across the cloud. The old method of fully encapsulating an OS and app stack in each virtual desktop machine creates enormous memory duplication and high dynamic random access memory usage. It also causes boot storms when hundreds of copies of Microsoft Windows and Office are delivered to virtual PCs each morning.
The new method -- using containers -- changes that. It’s still in its early days, but the container model eliminates multiple copies of the OS and apps and replaces them with a single copy. The cost is a slight loss of flexibility because all the virtual machines must use the same OS, but that’s a trivial problem in a cloud of hundreds of thousands of almost identical instance images.
With containers, each server loads a single OS image, from which it can derive hundreds of virtual desktops to achieve a much higher density of instances at a lower cost. The storage farm also benefits from a reduction in boot image traffic, which undermines a key use case for all-flash array storage.
Even so, using an all-flash array as the first storage tier makes a lot of sense because the typical array capacity should grow toward the petabyte scale. Some vendors will have to make a major adjustment in how they position their products, but any vendor with a strong lock on low-cost 3D NAND supplies will have a distinct advantage over the competition.
Breaking down the competition
The trade-off of standard solid-state drive (SSD) versus the proprietary all-flash array adds another complication to the mix. Small appliances with a block of ultra-fast SSD and an ARM front-end are economically viable competition for all-flash array storage, and the rise of SSD with native Ethernet interfaces may push the advantage closer to a drive-based approach.
The bottom line is that all-flash arrays are winning the race for now, but the finish line isn’t even in sight yet; the competition will likely catch up quickly. All-flash array vendors won’t be able to sustain their prices or rest on their laurels if they want to stay on top. The good news for the consumer is virtual desktops will become faster, cheaper and easier to deploy, and the boot storm will eventually be history.
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