The real advantage of high density NAND Flash is more its ability to carry out application workload acceleration than its capacity for storage, according to Flash storage vendor Fusion-io.
Speaking to Techworld last week, the company's chief executive David Flynn said that companies like EMC are approaching the problem from the wrong direction, integrating Flash into their storage arrays to speed up the read/write process, rather than harnessing its memory capabilities.
Fusion-io has built a storage memory platform that improves the processing capabilities within a data centre by relocating process-critical, or “active” data from centralised storage arrays to the server where it is being processed – a method known as data decentralisation.
“The thing that has been the choke point or the constraint on how much useful work you can get from a server hasn't been the amount of processing, but the amount of data that you can feed it,” said Flynn. “RAM is a way to feed it data, and disks are a way to feed it data, but RAM is too small and disks are too slow, so either way you can't get large quantities of data into the processor fast.”
Flynn said that the company's ioDrives have a hundred times the capacity of a memory module and thousands of times the performance of a disk drive. The devices plug directly into the server, meaning that the server can act as primary storage and access applications faster.
“I'm not saying it gets rid of your disk drives or memory, it allows those to be optimised – one for lots of capacity and the other for performance,” said Flynn. “So you still have RAM, you just don't need as much as it. You still have disks, you just don't need as many spindles.”
Flynn said the power is in being able to purchase performance separately from capacity, and scale the two independently. With today's storage arrays, improving performance means buying lots more mechanical disks, and you get capacity even if you didn't ask for it, he said. Satisfying those needs separately is cheaper, because you don't end up overbuying capacity in order to supply performance.
This is particularly significant in a virtualised environment, where the savings made on server consolidation are often dwarfed by the additional spend on the storage arrays. By plugging a Flash drive into a server, the data from the storage area network (SAN) is cached, so it is no longer necessary to keep adding disks to get performance.
“The biggest limiting factor on how many VMs you can put on a server is how much memory you put in it. If you had a huge amount of memory, you wouldn't care about your storage performance,” said Flynn. “This gives you that memory capacity, so you don't have to worry about the performance in your storage and can size it solely for capacity.”
By giving companies the ability to add performance from outside of the SAN, where vendors control the markup, they are able to scale things more cost effectively and benefit from buying more software licenses, added Flynn.
“This isn't just about the fundamental change of the medium, it's about the change of the market to an open market,” he said. “The open models win.”
Earlier this year, EMC introduced its own server-based product called VFCache, which combines Flash and caching technology to improve the performance of applications. The solution, announced at EMC World as 'Project Lightning', allows a copy of the “hottest” data to be stored on the flash card for fast and easy access.
EMC is now also working on 'Project Thunder', which it describes as a purpose-built, low-latency, server-networked, Flash-based appliance that is scalable and shareable. “Project Thunder will deliver I/Os measured in millions and timed in microseconds,” EMC said.