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Editor's note: SearchITChannel periodically publishes features on emerging technologies and standards of interest to service providers. This article examines NVM Express, generally known as the NVMe spec, or rather a group of specifications, in the flash storage space.
The transition from traditional hard disk storage to flash has been underway during the past few years. Many businesses are realizing significant performance boosts with the latter, and even more improvements are possible from emerging standards dubbed NVMe. These specifications boost performance in different systems and have evolved at varying rates. Consequently, businesses need assistance in taking advantage of the work, opening the door to new partner opportunities.
Moving from hard disk to flash improves performance, but the interfaces designed for the former are not fully efficient as the latter.
"The protocols used to enhance spinning media performance focused on the disk being the bottleneck," explained Scott Sinclair, senior analyst at Enterprise Strategy Group (ESG) Inc. "As flash has replaced hard disk, the bottleneck moved to other areas, like the system interconnect and the network."
Standards take shape
In response, vendors formed the NVM Express Work Group in 2011 and began crafting specifications to maximize flash performance. Three standards emerged:
- The NVMe spec is a register interface and command set for PCI Express attached storage.
- The NVMe over Fabrics spec enables tunneling the NVMe command set over traditional network interfaces, such as TCP/IP and Fibre Channel.
- The NVMe Management Interface is a command set and architecture for out of band management of NVM Express storage, and performs tasks, like discovering, monitoring and updating NVMe devices.
NVMe provides an alternative to the Small Computer System Interface (SCSI) and the Serial Advanced Technology Attachment (SATA) standards that connect host systems to peripheral storage devices. The new specification tried to address issues, like latency, performance and power consumption. The NVMe spec delivers significant performance improvements at the same price as SCSI or SATA solutions, according to Julia Palmer, research director at Gartner Inc.
NVMe has been endorsed by the major storage suppliers, like Cisco, Dell, Facebook, IBM, NetApp, Pure Storage Inc. and Intel. These companies have been shipping storage and server solutions for a year or two and the market uptick has been steady, according to ESG's Sinclair.
Network dimension: The NVMe over Fabrics spec
However, the standard is not a panacea. The NVMe spec is limited to distance of the PCI bus, which is a few hundred meters, as well as a small handful of devices.
Scott Sinclairsenior analyst, ESG
Consequently, the group began working on the NVMe over Fabrics spec, which is geared for network connections and shared storage. "The standard's organization's goal is to provide connectivity at 10 microseconds," Gartner's Palmer said. That work has proved challenging, so the vendors have been working on various techniques to meet that objective.
Because the work is still unfinished, the fabric standard has not been widely implemented. Chip vendors and startup storage suppliers, E8 Storage and Excelero, announced products, but mainstream vendors are waiting on the sidelines for clear resolutions to the technical challenges.
Filling the management gaps
The management standards designed to help businesses troubleshoot problem connections are also in an early stage. Tools for NVMe connections are starting to arrive, but products to manage the NVMe over Fabrics spec are in development and pilot stages rather than shipping products.
In many cases, companies will need to support both legacy hard disk storage and NVMe flash. The tools to manage such configurations are also in a fledging state. With hard disk, the bottleneck was disk I/O. With flash, the trouble spot is not as clear, so more sophisticated management tools are needed.
The changing landscape offers opportunities to channel partners. First customers need to be educated on what NVMe is and how it may impact their storage systems. Businesses must answer many questions: What is their application environment? Which applications need faster storage performance? How quickly will their infrastructure need to expand? Where does NVMe fit?
The move to flash has been taking place in the last few years. While the technology has the potential to enhance performance, items such as device interfaces need to be fine-tuned. The NVMe spec offers companies the ability to maximize storage performance, and the migration to these interfaces has begun. Companies need help making the transition, and resellers are in good position to provide that aid.