There may be a shortage in the supply of #DRAM main memory and #NAND flash memory that is having an adverse effect on the server and storage markets, but there is no shortage of vendors who are trying to push the envelope on clustered storage using a mix of these memories and others such as the impending #3DXPoint. #Micron Technology, which makes and sells all three of these types of memories, is so impatient with the rate of technological advancement in clustered flash arrays based on the NVM-Express protocol that it decided to engineer and launch its own product line. This is something that you don’t see a component supplier do very often, but it does happen. Intel has sold servers on and off for years under special circumstances to specific customers, and #Nvidia peddles its hybrid CPU-GPU DGX-1 systems, to name just two examples. It is always a bit peculiar when such vendors do this, and it is often because they want to help set the pace and speed up access to a technology so much that they just do it themselves. So it is with the SolidScale all-flash arrays from Micron, which were recently unveiled and which it hopes to get into the hands of early adopters later this fall and make generally available to any and all takers in early 2018. That is a pretty long lead time to tell customers about a product, too, and it is an indicator of just how eager Micron is to see its NVM-Express flash and QuantX 3D XPoint storage, which the SolidScale system is designed from the get-go to support, business take off. The all-flash array market is a crowded field with some pretty strong upstarts and incumbents, so it is hard to say how Micron will do as an array supplier. But no matter what, the SolidScale arrays provide an object lesson in what is wrong with non-volatile storage today as it is commonly deployed and what it might take to fix the problems. Andy Fisher, the senior product line manager at Micron who joined the company a year and a half ago after stints at Compaq and Hewlett Packard Enterprise, walked The Next Platform through the issues and the techniques that Micron has come up with the resolve them. Given that Micron sells flash and soon 3D XPoint storage devices as well as flash memory to those who also want to sell such devices in turn to datacenters, you might think Micron would just keep mum about the whole issue of the inefficient use of non-volatile storage in servers these days. Micron wants to fix these issues to drive adoption, just like Intel set its techies to work on the NVM-Express protocol several years ago to get the heritage SAS and SCSI protocol stack out of the link between the central processor and the flash memory, which is not a rotating media. NVM-Express chops out all that legacy junk and allows for flash devices to more directly link to the compute complex over the PCI-Express peripheral bus, which increases the effective bandwidth and reduces the latency of I/O operations between the CPU and the flash. Right now, there are a number of issues that are keeping NVM-Express storage from being widely adopted, and Fisher rattled them off for us. Servers in the “Haswell” and “Broadwell” Xeon generations – meaning over the past three years – might have had two or four NVM-Express ports hanging off the processing complex. This was good for a higher speed caching layer within the system, but it was not ideal in that all flash storage could not link in this fashion. Other issues that NVM-Express faces are the relatively high cost between regular SSDs and those with NVM-Express ports (something Micron could do something about in the future but has made no promises in this regard), but this premium is somewhat mitigated by the fact that you do not need an intermediate storage controller between the flash and the CPU on the peripheral bus. The relative immaturity of the NVM-Express over Fabrics extension to the protocol is an issue, but the plan is to allow for a pool of non-volatile storage to be accessible to multiple servers using Ethernet or InfiniBand networks that link the storage and the servers together in a mesh.
https://www.nextplatform.com/2017/05/08/impatient-fabrics-micron-forges-nvm-express-arrays/
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