Category: Fibre Channel

Fibre Channel SAN Hosts and Targets Q&A

John Kim
At our recent SNIA Networking Storage Forum (NSF) webcast “How Fibre Channel Hosts and Targets Really Communicate” our Fibre Channel (FC) experts explained exactly how Fibre Channel works, starting with the basics on the FC networking stack, link initialization, port types, and flow control, and then dove into the details on host/target logins and host/target IO. It was a great tutorial on Fibre Channel. If you missed it, you can view it on-demand. The audience asked several questions during the live event. Here are answers to them all: Q. What is the most common problem that we face in the FC protocol? A. Much the same as any other network protocol, congestion is the most common problem found in FC SANs. It can take a couple of forms including, but not limited to, host oversubscription and “Fan-in/Fan-out” ratios of host ports to storage ports, but it is probably the single largest generator of support cases. Another common problem is the ‘Host cannot see target’ kind of problem. Read More

Demystifying the Fibre Channel SAN Protocol

John Kim
Every wonder how Fibre Channel (FC) hosts and targets really communicate? Join the SNIA Networking Storage Forum (NSF) on September 23, 2021 for a live webcast, “How Fibre Channel Hosts and Targets Really Communicate.” This SAN overview will dive into details on how initiators (hosts) and targets (storage arrays) communicate and will address key questions, like:
  • How do FC links activate?
  • Is FC routable?
  • What kind of flow control is present in FC?
  • How do initiators find targets and set up their communication?
  • Finally, how does actual data get transferred between initiators and hosts, since that is the ultimate goal?
Read More

Beyond NVMe-oF Performance Hero Numbers

Erik Smith
When it comes to selecting the right NVMe over Fabrics™ (NVMe-oF™) solution, one should look beyond test results that demonstrate NVMe-oF’s dramatic reduction in latency and consider the other, more important, questions such as “How does the transport really impact application performance?” and “How does the transport holistically fit into my environment?” To date, the focus has been on specialized fabrics like RDMA (e.g., RoCE) because it provides the lowest possible latency, as well as Fibre Channel because it is generally considered to be the most reliable. However, with the introduction of NVMe-oF/TCP this conversation must be expanded to also include considerations regarding scale, cost, and operations. That’s why the SNIA Networking Storage Forum (NSF) is hosting a webcast series that will dive into answering these questions beyond the standard answer “it depends.” Read More

Notable Questions on NVMe-oF 1.1

Tim Lustig
At our recent SNIA Networking Storage Forum (NSF) webcast, “Notable Updates in NVMe-oF™ 1.1” we explored the latest features of NVMe over Fabrics (NVMe-oF), discussing what’s new in the NVMe-oF 1.1 release, support for CMB and PMR, managing and provisioning NVMe-oF devices with SNIA Swordfish™, and FC-NVMe-2. If you missed the live event, you can watch it here. Our presenters received many interesting questions on NVMe-oF and here are answers to them all: Read More

Storage Congestion on the Network Q&A

Tim Lustig
As more storage traffic traverses the network, the risk of congestion leading to higher-than-expected latencies and lower-than expected throughput has become common. That’s why the SNIA Networking Storage Forum (NSF) hosted a live webcast earlier this month, Introduction to Incast, Head of Line Blocking, and Congestion Management. In this webcast (which is now available on-demand), our SNIA experts discussed how Ethernet, Fibre Channel and InfiniBand each handles increased traffic. The audience at the live event asked some great questions, as promised, here are answers to them all. Q. How many IP switch vendors today support Data Center TCP (DCTCP)? Read More

Network Speeds Questions Answered

John Kim
Last month, the SNIA Networking Storage Forum (NSF) hosted a webcast on how increases in networking speeds are impacting storage. If you missed the live webcast, New Landscape of Network Speeds, it’s now available on-demand. We received several interesting questions on this topic. Here are our experts’ answers: Q. What are the cable distances for 2.5 and 5G Ethernet? A. 2.5GBASE-T and 5GBASE-T Ethernet are designed to run on existing UTP cabling, so it should reach 100 meters on both Cat5e and Cat6 cabling. Reach of 5GBASE-T on Cat 5e may be less under some conditions, for example if many cables are bundled tightly together. Cabling guidelines and field test equipment are available to aid in the transition. Read More

Intro to Incast, Head of Line Blocking, and Congestion Management

Tim Lustig
For a long time, the architecture and best practices of storage networks have been relatively well-understood. Recently, however, advanced capabilities have been added to storage that could have broader impacts on networks than we think. The three main storage network transports – Fibre Channel, Ethernet, and InfiniBand – all have mechanisms to handle increased traffic, but they are not all affected or implemented the same way. For instance, utilizing a protocol such as NVMe over Fabrics will offer very different methodologies for handling congestion avoidance, burst handling, and queue management when looking at one networking in comparison to another. Read More

The Impact of New Network Speeds on Storage

John Kim
In the last few years, Ethernet equipment vendors have announced big increases in line speeds, shipping 25, 50, and 100 Gigabits-per -second (Gb/s) speeds and announcing 200/400 Gb/s. At the same time Fibre Channel vendors have launched 32GFC, 64GFC and 128GFC technology while InfiniBand has reached 200Gb/s (called HDR) speed. But who exactly is asking for these faster new networking speeds, and how will they use them? Are there servers, storage, and applications that can make good use of them? How are these new speeds achieved? Are new types of signaling, cables and transceivers required? How will changes in PCIe standards and bandwidth keep up? And do the faster speeds come with different distance limitations? Read More

Introducing the Networking Storage Forum

John Kim

At SNIA, we are dedicated to staying on top of storage trends and technologies to fulfill our mission as a globally recognized and trusted authority for storage leadership, standards, and technology expertise. For the last several years, the Ethernet Storage Forum has been working hard to provide high quality educational and informational material related to all kinds of storage.

From our “Everything You Wanted To Know About Storage But Were Too Proud To Ask” series, to the absolutely phenomenal (and required viewing) “Storage Performance Benchmarking” series to the “Great Storage Debates” series, we’ve produced dozens of hours of material.

Technologies have evolved and we’ve come to a point where there’s a need to understand how these systems and architectures work – beyond just the type of wire that is used. Today, there are new systems that are bringing storage to completely new audiences. From scale-up to scale-out, from disaggregated to hyperconverged, RDMA, and NVMe-oF – there is more to storage networking than just your favorite transport. Read More

A Q&A from the FCoE vs. iSCSI vs. iSER Debate

Tim Lustig
It’s become quite clear to those of us in the SNIA Ethernet Storage Forum (ESF) that everyone loves a great debate. We’ve proved that with our “Great Storage Debates” webcast series which has had over 3,500 views in just a few months! Last month we had another friendly debate on FCoE vs. iSCSI vs. iSER. If you missed the live event, you can watch it now on-demand. Our live audience asked a lot of interesting questions. As promised, here are answers to them all. Q. How often are iSCSI offload adapters used in customer environments as compared to software initiators?  Can these adapters be used for all IP traffic or do they only run iSCSI? Read More