The pieces are starting to fall into place for even higher performing flash storage with lower latency through the use of Nonvolatile Memory Express (NVMe) over Fibre Channel (FC).
Broadcom (part of Avago Technologies) this week made available to OEMs Emulex Gen 6 FC host bus adapters (HBAs) that support NVMe over FC. Broadcom claims the updated Gen 6 FC HBAs could help to lower latency by more than 50% and boost overall performance by more than 25% with SSDs that use NVMe, rather than Small Computer System Interface (SCSI), to transfer data and commands between host and target storage devices.
SCSI was designed years ago for slower storage media, such as hard disk drives (HDDs) and tape. The newer NVMe specification streamlines the I/O stack to facilitate higher performance, lower latency and lower power consumption with faster solid-state drives (SSDs). NVMe over Fabrics, include FC-NVMe, enables the NVMe command set to work across the network with external storage.
“As we’ve learned in talking to customers, the network’s becoming more and more of a bottleneck just because storage has gone from spinning media to these really low-latency architectures that are really fast,” said Brandon Hoff, director of product management at Broadcom. “So our focus with this solution is to hammer down latency and be the fastest network out there for moving NVMe traffic across the fabric.”
Last month, an industry consortium published version 1.0 of the NVMe over Fabrics specification. An NVMe Fabrics working group – which includes Broadcom – also published Linux target and driver code for inclusion in the Linux kernel. Hoff said the Linux distributions that enterprises typically use, such as Red Hat and SUSE, and other operating systems, such as Windows and VMware, should support FC-NVMe over time.
Server and storage operating systems, FC drivers, and HBAs will ultimately need to support NVMe over FC, according to Hoff. He said Broadcom updated and optimized its FC drivers and HBA firmware to support FC-NVMe and made available a reference architecture for vendors and early adopters. He said Broadcom Emulex has been demonstrating its Gen 6 HBAs, which support NVMe and SCSI, to server and storage vendors for several months.
“It was a very light lift for us to add NVMe as a protocol. Fibre Channel actually has multiple protocols that can run over it. FCP is the one that uses SCSI. And now we’re adding NVMe as a new protocol that runs over Fibre Channel,” Hoff said.
Hoff predicted the first phase of products to support NVMe over FC will be “just a bunch of flash” (JBOF) devices. He said the hardware is available, and the software needs to catch up. Hoff expects server OEMs to support FC-NVMe as they transition to Intel’s “Purley” enterprise platform in “2017ish.”
“NVMe all-flash arrays will be a little in the future,” Hoff said. “Some are [currently] moving to NVMe drives on the backend, but there’s SCSI on the front end. So they do protocol conversion. They bring a SCSI command off Fibre Channel on the front side, then they have to convert it to NVMe so it talks to NVMe drives.”
Once all-flash arrays support NVMe on the front end, there will no need for the translation, and latency will drop even further. In the meantime, Fortune 1000 FC users will know that “the hardware just works” as they decide to move to NVMe-based storage, Hoff said.
“If you want to deploy NVMe in your data center, all you have to do is plug an NVMe array into the Fibre Channel network. You don’t have to update the Fibre Channel, the drivers and the host,” Hoff said.