EMC's DSSD introduces the PCIe flash appliance

It’s always interesting when a new storage technology comes along, not least because we have to figure out what exactly we’re looking at.

Under the microscope this time is the fruit of EMC’s acquisition of DSSD, a Silicon Valley startup bought last month.

EMC calls it “rack-scale flash” and Dan Cobb, CTO of the flash division at EMC, told me DSSD had tried to do three things in its short existence.

These are, he said: “Achieve massive storage density, using flash and other components to build an all-flash appliance – as distinct from an array – in terms of the number of chips that can be co-located.”

“Build a connection to hosts that is massively parallel – using the Gen 3 PCIe connect – to connect between 8,000 and 16,000 independent flash dies directly to the host with tremendously low latency, compared to one drive that that typically holds 16 dies via a single SAS or SATA interface.”

“With all flash management, wear levelling, garbage collection etc integrated into system software to achieve incredible effectiveness.”

What we have here is a PCIe-attached flash appliance with capacity of “hundreds of TB, approaching petabytes” that can operate as direct-attached storage (DAS) or, it is claimed, as an extension to RAM.

EMC is aiming it at in-memory database use and big data for real time operations.

Cobb said EMC would be working on three forms of connectivity for DSSD. These would be:

·         As a traditional block interface using NVME (non-volatile memory express) to connect via PCIe.

·         Via custom APIs. DSSD will have developed for it new API primitives, for example a plugin for HDFS low latency operations tailored for specific applications.

·         In-memory database use – for example with MongoDB – that will result in virtual memory primitives that allow the database to see one giant memory store in DSSD.

So, it looks like we have a new beast on our hands, a PCIe-connected flash appliance for use as extremely low latency DAS and/or as a RAM extension.

It’s a bit like a server-side flash store but with capacity that massively outscales existing products, which will be able to, as Cobb put it, be used as “a very fast failover, for example running multiple SAP HANA instances.”

And at the same time it might be something like the new memory channel storage products now emerging. Sure, it’s not DIMM-connected but the very low latency claimed by EMC may allow it to become a RAM extension.

Anyway, more will certainly become clear over the next year, with EMC planning to “harden” the product and go for some kind of product launch this time next year.