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    How Ethernet RDMA Protocols iWARP and RoCE Support NVMe over Fabrics

    January 6th, 2016

    NVMe (Non-Volatile Memory Express) over Fabrics is of tremendous interest among storage vendors, flash manufacturers, and cloud and Web 2.0 customers. Because it offers efficient remote and shared access to a new generation of flash and other non-volatile memory storage, it requires fast, low latency networks, and the first version of the specification is expected to take advantage of RDMA (Remote Direct Memory Access) support in the transport protocol.

    Many customers and vendors are now familiar with the advantages and concepts of NVMe over Fabrics but are not familiar with the specific protocols that support it. Join us on January 26th for this live Webcast that will explore and compare the Ethernet RDMA protocols and transports that support NVMe over Fabrics and the infrastructure needed to use them. You’ll hear:

    • Why NVMe Over Fabrics requires a low-latency network
    • How the NVMe protocol is mapped to the network transport
    • How RDMA-capable protocols work
    • Comparing available Ethernet RDMA transports: iWARP and RoCE
    • Infrastructure required to support RDMA over Ethernet
    • Congestion management methods

    The event is live, so please bring your questions. We look forward to answering them.


    Next Webcast: The 2015 Ethernet Roadmap for Networked Storage

    May 5th, 2015

    The ESF is excited to announce our next live Webcast, “The 2015 Ethernet Roadmap for Networked Storage.”

    For over three decades, Ethernet has advanced on a simple “powers-of-ten” speed increases, and this model has served the industry well.  Ethernet is changing in big ways and the Ethernet Alliance has captured the latest changes in the 2015 Ethernet Roadmap.

    On June 30th at 10:00 a.m. PT an expert panel comprised of Scott Kipp, President of the Ethernet Alliance, David Chalupsky, Chair IEEE P802.3bq/bz TFs and the Ethernet Alliance BASE-T Subcommittee and myself will present the Ethernet Alliance’s 2015 Ethernet Roadmap for the networking technology that underlies most of future network storage.

    SNIA has focused on protocols and usage models and more or less just takes Ethernet for granted.  The biggest technology disruption in the storage space is the emergence into the mainstream of Non-Volatile Memory (NVM), FLASH in particular.  NVM increasingly moves system bottlenecks from the storage subsystem to the network.  Developments in NVM — most recently 3D FLASH — assure that the cost per GB will continue aggressive declines and demand for bandwidth will go up.  NVM will become more prevalent, making the roadmap for Ethernet increasingly more important to the storage networking community.

    This will be a live and interactive session. I encourage you to register now and bring your questions for our experts. I hope to see you on June 30th.


    SNIA ESF Leadership Welcomes Chad Hintz

    March 12th, 2015

    The ESF continues our busy schedule hosting informative Webcasts, writing and publishing articles and participating at industry conferences. 2015 also brings a change in ESF leadership. I’d like to welcome Chad Hintz of Cisco as our newest ESF board member. Chad has been elected as chair of our Storage over Ethernet Special Interest Group (SIG).

    The Storage over Ethernet SIG is focused on a growing trend among modern data centers to deploy consolidated Ethernet networks as the primary network infrastructure for all LAN and storage traffic. Technologies such as Data Center Bridging (DCB), Fibre Channel over Ethernet (FCoE) among others, offer organizations a robust environment to support mixed workloads with each using the most appropriate protocol (including NFS, SMB and iSCSI) over a shared Ethernet physical transport. The Storage over Ethernet SIG offers educational and thought leadership materials related to these technologies and the business value they offer to organizations of all sizes. Especially appreciated by our audience is that this information comes from SNIA and thus is vendor-neutral.

    Chad brings a wealth of expertise to ESF. He is a Technical Solutions Architect focusing on designing enterprise solutions for customers around data center technologies. He holds 3 CCIEs in routing and switching, security and storage and has held certifications from Novell, VMware, and Cisco. We’re confident his expertise and passion for Ethernet Storage will be a big asset to our group.

    We are looking forward to having Chad on our team to help guide the many activities we have planned this year. Other members of the 2015 board include myself as ESF chair, Alex McDonald (NetApp), and Mike Jochimsen (Emulex).

    As I mentioned, the ESF is busy creating vendor-neutral educational on Ethernet connected storage networking technologies. I encourage you to check out some of our recent and upcoming content:

    Upcoming Webcast – Visions for Ethernet Connected Drives

    On-demand Webcast – Benefits of RDMA in Accelerating Ethernet Storage Connectivity

    Article – Cloud File Services

    Article – Weave Your Cloud with a Data Fabric

     

     


    Benefits of RDMA in Accelerating Ethernet Storage Q&A

    March 9th, 2015

    At our recent live Webcast “Benefits of RDMA in Accelerating Ethernet Storage Connectivity” experts from Emulex, Intel and Microsoft had an insightful discussion on the ways RDMA is having an impact on Ethernet storage. The live event was attended by nearly 200 people and feedback was overwhelming positive with several attendees thanking us for our vendor neutral presentation and one attendee commenting that it was, “Probably the most clearly comprehensible yet comprehensive webinar I’ve attended in some time.” If you missed the Webcast, it’s now available on demand. We did not have time to get to everyone’s questions, so as promised, below are answers to all of them. If you have additional questions, please ask them in the comments section in this blog and we’ll get back to you as soon as possible.

    Q. Is RDMA over RoCEv2 in production?

    A. The IBTA released the RoCEv2 Specification in September 2014.  In order to support that specification changes may be required across the RDMA stack, including firmware, drivers & operating systems.  Schedules for implementation of that specification will vary by operating system.  For example, the OpenFabrics Alliance (OFA) has not released an Open Fabrics Enterprise Distribution (OFED) version that implements that standard yet, although it is in process now.  Once OFA completes their OFED stack implementation, the Linux distribution vendors will then incorporate and support the updated OFED stack.  Implementations provided prior to full OFA and Distro vendor support would be preliminary, potentially incompatible with the OFED release, and require confirmation by the distro vendor with regard to the nature/level of support they would be providing

    Q. I would have liked a list of Windows applications that take advantage of SMB Direct – both in a Hyper-V host or bare metal.

    A. In Windows, any file-based application can make use of SMB3 and SMB Direct due to the native file-based programming interface support. No application changes are required. For certain enterprise applications such as Hyper-V and SQL Server, SMB3 is officially supported, and more information can be found in the product catalog at www.microsoft.com.

    Q. Are there any particular benefits in using one network protocol over another for SMB Direct/RDMA (iWARP vs. RoCE vs. IB)?

    A. There are no hard and fast rules; any adapter or protocol can be suitable for many scenarios. Of the Ethernet-based protocols we considered in today’s webcast

    • iWARP offers the benefit of operation over TCP with its reliability and routability, well-suited to a broad range of installed infrastructure.
    • RoCE offers a lightweight, efficient protocol when a DCB-enabled switched fabric is available. RoCE, however, is not routable.
    • RoCEv2 offers similar properties to RoCE, with the possibility to scale to larger routed and DCB-enabled fabrics.

    Q. Who are the vendors offering iWARP capable RNICs?

    A. Chelsio Communications has production iWARP adapters today, and both Intel and Qlogic have publicly committed to future iWARP controllers.

    Q. How much testing has been done with SMB3, and in particular SMB direct, over WAN connections?

    A. The SMB2 protocol was originally designed to adapt to WAN scenarios, and supports a credit-based management of large amounts of data to be outstanding, to make best use of WAN-type long pipes. The SMB3 protocol retains these design attributes, and the SMB Direct protocol also supports similar deep pipelining. The iWARP protocol, being layered on standard TCP, is well suited to such deployments, and RoCE WAN adapters are potentially available. Please contact the respective technology vendors for information on any available testing results.

    Q. I love a future webcast for RDMA enabled distributed filesystems.

    A. Thanks for the suggestion! We’re always looking for ideas for future webcasts and SNIA-ESF will consider this as a potential follow-on.

    Q. Is Live Migration the scenario where “packet size” is 1MB?

    A. All SMB Direct scenarios have workloads that range anywhere up to 8MB. For large file copies, most SMB3 clients request from 1MB to 8MB per operation, for Hyper-V live migration, transfers are typically similar, during the bulk transfer phase.

    Q. SMB3 is being compared to FC for enterprise. If Ethernet based protocols are of interest, wouldn’t FCoE give the same performance as FC (same stack) vs. SMB3?

    A. SMB3 with SMB Direct enables many workloads not possible with Fibre Channel over Ethernet, and performance comparisons are therefore difficult. Perhaps another SNIA webcast could investigate this!

    Q. Regarding your SMB direct example with lots of small operations, how do you deal with the overhead of registering and unregistering buffers for the RDMA operations?

    A. As answered later in the session, the registration and unregistration is not a protocol matter, but in the case of the Windows implementation, it is strictly performed for the specific buffers of each operation, which is critical for security, data integrity, and system protection. The standard “Fast Register Work Request” method is used, and careful implementation has shown that the overhead does not negatively impact performance, even for small I/O (4KB/operation). Check out Jose Barreto’s blog, which contains many benchmark results.

    Q. But isn’t Live Migration done in 1MB “chunks”? So not “small” I/Os?

    A. As answered later in the session, Hyper-V Live Migration is done in several phases, the first phase is the initial bulk copy of memory, done in large chunks, but immediately after it a second phase of copying individual pages which were dirtied by the live-running VM is performed. These operations are typically 4KB. Note: The faster the initial phase goes, the less work there is in this second phase, but in both phases, the faster, the better, and RDMA accelerates both.

    Q. Are iSER and iWARP alternatives to one another?

    A.  iWARP is an RDMA protocol, and iSER is a mapping of iSCSI to iWARP, as well as RoCE/InfiniBand.

    Q. What’s Intel’s roadmap for RoCE and/or iWARP?

    A. Intel is committed to iWARP and plans to incorporate it in future server chipsets and SOCs. See http://www.intel.com/content/www/us/en/ethernet-products/accelerating-ethernet-iwarp-video.html for more information.

    Q. Is there any other Transport being used other than IB to create a reliable transport for RoceV2? Puristically it is possible?

    A. RoCE was developed to leverage Infiniband as much as possible.  For that reason, the Infiniband transport was chosen when the RoCE standard was developed.  As the RoCEv2 standard was developed, the underlying Infiniband network protocol was replaced with IPv4 / IPv6 in order to provide the layer 3 routability and UDP to provide stateless encapsulation (and indication) of the Infiniband transport header that was retained.  While it may be possible to develop a reliable transport to replace Infiniband, the RoCE standards body has elected not to go that route as of this writing.

     

     

     


    Relentless Advance Of Ethernet – And Ethernet Storage Networking

    March 31st, 2014

    As one Cisco colleague once said to me, “After the nuclear holocaust, there will be two things left: cockroaches and Ethernet.”  Not sure I like Ethernet’s unappealing company in that statement, but the truth it captures is that Ethernet, now entering its fifth decade (wow!), is ubiquitous and still continuing to advance at a breathtaking pace.  And as it advances, it advances the capabilities of storage networking based on the Ethernet backbone, be it file storage like NFS or SMB or block storage like iSCSI or FCoE.

    Most recent evidence of Ethernet’s continuing and relentless evolution is illustrated in the 28 March 2014 announcement from the Ethernet Alliance congratulating the IEEE on formation of their IEEE P802.3bs™ Task Force:

    The new group is chartered with the development of the IEEE P802.3bs 400 Gigabit Ethernet (GbE) project, which will define Ethernet Media Access Control (MAC) parameters, physical layer specifications, and management parameters for the transfer of Ethernet format frames at 400 Gb/s. As the leading voice of the Ethernet ecosystem, the Ethernet Alliance is ideally positioned to support this latest move towards standardizing and advancing 400Gb/s technologies through efforts such as the launch of the Ethernet Alliance’s own 400 GbE Subcommittee.

    Ethernet is in production today from multiple vendors at 40GbE and supports all storage protocols, including FCoE, at those speeds.  Market forecasters expect the first 100GbE adapters to appear in 2015.  Obviously, it is too early to forecast when 400GbE will arrive, but the train is assuredly in motion.  And support for all the key storage protocols we see today on 10GbE and 40GbE will naturally extend to 100GbE and 400GbE.  Jim O’Reilly makes similar points in his recent Information Week article, “Ethernet: The New Storage Area Network where he argues, “Ethernet wins on schedule, cost, and performance.”

    Beyond raw transport speed, the rich Ethernet infrastructure offers techniques to catapult your performance even beyond the fastest single-pipe speed.  The Ethernet world has established techniques for what is alternately referred to as link aggregation, channel bonding, or teaming.  The levels available are determined by the capabilities provided in system software and what switch vendors will support.  And those capabilities, in turn, are determined by what they respectively see as market demand.  VMware, for example, today will let you bond eight 10GbE channels into a single 80GbE pipe.  And that’s today with mainstream 10GbE technology.

    Ethernet will continue to evolve in many different ways to support the needs of the industry.  Serving as a backbone for all storage networking traffic is just one of many such roles for Ethernet.  In fact, precisely because of the increasing breadth of usage models Ethernet supports, it will also continue to offer cost advantages.  The argument here is a very simple volume argument:

    Total Server-class Adapter and LOM Market Ports

    crehan-relentless-ethernet-420

    Enough said, except to also note that volume is what funds speed roadmaps.

     

     


    2013 in Review and the Outlook for 2014 – A SNIA ESF Perspective

    January 28th, 2014

    Technology continues to advance rapidly. Making sense of it all can be a challenge. At the SNIA Ethernet Storage Forum, we focus on storage technologies and solutions enabled by and associated with Ethernet Networks. Last year, we modified the charters of our two Special Interest Groups (SIG) to address topics about file protocols and storage over Ethernet. The File Protocols SIG includes the prior focus on Network File System (NFS) related topics and adds discussions around Server Message Block (SMB / CIFS). We had our first webcast last November on the topic of SMB 3.0 and it was our best attended webcast ever. The Storage over Ethernet SIG focuses on general Ethernet storage topics as well as more information about technologies like FCoE, iSCSI, Data Center Bridging, and virtual networking for storage. I encourage you to check out other articles on these hot topics in this SNIAESF blog to hear from our member experts as well as guest posts from leading analysts.

    2013 was a busy year and we are already kickin’ it in 2014. This should be an exciting year in IT. Data storage continues to be a hot sector especially in the areas of All-Flash and Hybrid arrays. This year, we will expect to see new standards coming out of the T11 committee for Fibre Channel and possibly FCoE as well as progress in high speed Ethernet networks. Lower cost network interconnects will facilitate adoption of high speed networks in the small to midsize business segment. And a new conversation around “Software Defined…” should push a lot of ink in trade rags and other news sources. Oh, and don’t forget about the “Internet of Things”, mobile solutions, and all things Cloud.

    The ESF will be addressing the impact on Ethernet storage solutions from these hot technologies. Next month, on February 18th, experts from the ESF, along with industry analysts from Dell’Oro Group will speak to the benefits and best practices of deploying FCoE and iSCSI storage protocols. This presentation “Use Cases for iSCSI and Fibre Channel: Where Each Makes Sense” will be part of an upcoming BrightTalk Summit on Storage Networking. I encourage you to register for this session. Additionally, we will be publishing a couple of white papers on file-based storage and a review of FCoE and iSCSI in storage applications.

    Finally, SNIA will be kicking off its first year of the new user conference, Data Storage Innovation Conference. This will be one of the few storage focused user conferences in the market and should be quite interesting.

    We’re excited about our growing membership and our plans for 2014. Our goal is to advance application of innovative technologies and we encourage you to send us mail or comment below with topics that are of interest to you.

    Here’s to an exciting 2014!


    How is 10GBASE-T Being Adopted and Deployed?

    January 8th, 2013

    For nearly a decade, the primary deployment of 10 Gigabit Ethernet (10GbE) has been using network interface cards (NICs) supporting enhanced Small Form-Factor Pluggable (SFP+) transceivers. The predominant transceivers for 10GbE are Direct Attach (DA) copper, short range optical (10GBASE-SR), and long-range optical (10GBASE-LR). The Direct Attach copper option is the least expensive of the three. However, its adoption has been hampered by two key limitations:

    - DA’s range is limited to 7m, and

    - because of the SFP+ connector, it is not backward-compatible with existing 1GbE infrastructure using RJ-45 connectors and twisted-pair cabling.

    10GBASE-T addresses both of these limitations.

    10GBASE-T delivers 10GbE over Category 6, 6A, or 7 cabling terminated with RJ-45 jacks. It is backward-compatible with 1GbE and even 100 Megabit Ethernet. Cat 6A and 7 cables will support up to 100m. The advantages for deployment in an existing data center are obvious. Most existing data centers have already installed twisted pair cabling at Cat 6 rating or better. 10GBASE-T can be added incrementally to these data centers, either in new servers or via NIC upgrades “without forklifts.” New 10GBASE-T ports will operate with all the existing Ethernet infrastructure in place. As switches get upgraded to 10GBASE-T at whatever pace, the only impact will be dramatically improved network bandwidth.

    Market adoption of 10GBASE-T accelerated sharply with the first single-chip 10GBASE-T controllers to hit production. This integration become possible because of Moore’s Law advances in semiconductor technology, which also enabled the rise of dense commercial switches supporting 10GBASE-T. Integrating PHY and MAC on a single piece of silicon significantly reduced power consumption. This lower power consumption made fan-less 10GBASE-T NICs possible for the first time. Also, switches supporting 10GBASE-T are now available from Cisco, Dell, Arista, Extreme Networks, and others with more to come. You can see the early market impact single-chip 10GBASE-T had by mid-year 2012 in this analysis of shipments in numbers of server ports from Crehan Research:

     

    Server-class Adapter & LOM 10GBASE-T Shipments

    Note, Crehan believes that by 2015, over 40% of all 10GbE adapters and controllers sold that year will be 10GBASE-T.

    Early concerns about the reliability and robustness of 10GBASE-T technology have all been addressed in the most recent silicon designs. 10GBASE-T meets all the bit-error rate (BER) requirements of all the Ethernet and storage over Ethernet specifications. As I addressed in an earlier SNIA-ESF blog, the storage networking market is a particularly conservative one. But there appear to be no technical reasons why 10GBASE-T cannot support NFS, iSCSI, and even FCoE. Today, Cisco is in production with a switch, the Nexus 5596T, and a fabric extender, the 2232TM-E that support “FCoE-ready” 10GBASE-T. It’s coming – with all the cost of deployment benefits of 10GBASE-T.

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