I recently attended the Persistent Memory Summit (PMS), a Storage Networking Industry Association (SNIA) event. Why was a storage industry organization focusing on memory? Well, the theme was “Delivering on the Convergence of Storage and Memory.” A bold statement like that prompts the engineer in me to say “Hold up! I still see memory and storage as very different. Are they converging or colliding?”
High speed, high density flash chips have been transforming the storage industry for the last few years. With the rise of flash, the NVMExpress.org community has formed to define the low-latency, super-parallel NVMe (Non-Volatile Memory Express) protocol, a common software interface to PCIe-based solid state memory modules. NVMExpress.org then created a related spec, NVMe over Fabrics, to extend the reach of the NVMe protocol to datacenter scale. And bingo, NVMe became a relevant storage networking topic. So, yeah, convergence, right?
Well, it turns out that just because NVMe has the word “memory” doesn’t make it memory-centric. Some PMS speakers highlighted that, even though NVMe was driven by flash memory, its “semantics” are not ideal for memory. Flash is a rather block-ish technology, and so is NVMe; the smallest access defined for NVMe is a 512-byte block, which works great for storage and flash. On the other hand, some new technologies, like 3D XPoint, offer more granular accesses. On the third hand (I sound like an economist), byte-sized memory accesses don’t make efficient use of the PCI bus. Hmmm.
I mused some more on a, um, handful of memory / storage questions, like “How much time and effort do we usually invest to avoid errors?” Short answers: For memory, not much. For storage (especially enterprise storage), a fair bit. We see this in our infrastructure and purchasing decisions. If you’re using flash for memory-oriented use cases, maybe a best-effort, commodity infrastructure is what you want. But for enterprise storage, chances are you want a premium, robust datacenter infrastructure. And, no surprise, NVMe over Fibre Channel has what you need. It runs like greased lightning on Brocade’s Gen 5 and Gen 6 solutions, including our brand-new NVMe-ready entry-level switch.
As thrilling as flash and NVMe are, I, for one, am comforted to know that my path to a rocket-fast future remains in good hands. But one challenge of our fast-paced present is that, with so much information flying around, the details can be difficult to keep track of. Several of my field-based colleagues mentioned that customers were facing just this kind of challenge around NVMe over Fibre Channel. We needed a “handy” overview to cover the main points of the technology, so… yep, I put my hand up. “NVMe over Fibre Channel for Dummies” is now available for your reading pleasure. I will be on hand at Dell EMC World in Las Vegas to present “Brocade: The Future of Flash: NVMe Over Fibre Channel” on Monday, May 8, 4:30 p.m. in Lando 4201A, followed by a book signing at the Brocade booth #909.
(image credits: http://www.tbo.com/news/education/crossing-guards-hit-the-streets-for-start-of-school-20150823/ https://mycameramyeyes.wordpress.com/2012/01/26/the-hands-that-hold-my-heart/ )