The NVMe/TCP Dating App!
Fri, 18 Aug 2023 13:31:38 -0000
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Did you know that online dating started in 1959 using a mainframe computer with punch cards? Of course, it has come a long way since then, and now, even Dell Technologies has created a dating app. But it’s not for lonely hearts; it’s for NVMe/TCP servers and storage!
Over the last few years, a new storage networking technology has emerged: NVMe/TCP. This new specification gives us a Fibre Channel-like experience over an IP network. But what happens when servers and storage (aka endpoints) come online and wish to meet like-minded NVMe/TCP individuals in their area? Alone and lost in the Ether(net), they wait to be set up with a friend of a friend who, hopefully, speaks the same language, is a good listener, and maybe even has a GSOH? Or they could just register with Dell SmartFabric Storage Software!
NVMe/TCP endpoints register with the Centralized Discovery Controllers (CDCs) in the SFSS virtual machine. Here’s how it will work:
Compatible endpoints look for a CDC by sending out multicast DNS queries. Once the CDCs in SFSS have responded, the endpoints register by sending their name and dating profile, or “Log Page.” For endpoints that operate according to specifications TP-8009 and TP-8010, the discovery and registration process will be fully automated.
Endpoints subscribe to the SFSS’s notification service by sending an Asynchronous Event Request (AER). When a change occurs, such as a new storage subsystem, or an endpoint’s relationship status changes to “It’s complicated,” the registered endpoints are notified. This is called Asynchronous Event Notification (AEN) and is like Fibre Channel’s Registered State Change Notification (RSCN) service.
Next, we need a “match-maker.” The SFSS administrator will add hosts and storage to zones so that they reach out to each other directly.
The hosts are now able to connect and access the storage over high speed ethernet.
Here’s where it gets a bit awkward…
If, like me, you come from an application networking background, you’re used to setting up a network that gets a packet from A to B. However, with storage networking, we need a network that gets packets from A1 and A2, to B1, B2, B3, and B4. “Multi-pathing” is key! Storage networking is rather promiscuous compared to application networking! And, if you’re from a storage networking background, you might be thinking, “But what about single-initiator and single-target zoning?” Well, that’s not best practice either anymore. Once zoning is configured, hosts will connect with all accessible subsystems in the zone for optimal resiliency.
What does the network look like?
The people who designed NVMe/TCP took the lessons they learned from Fibre-Channel and applied them wisely. In FC, the convention is to deploy switches that will only bridge traffic between hosts and storage. Storage networks favor resiliency over redundancy, creating multiple active paths instead of creating idle paths ready to take over in the event of a failure.
We cover network planning in detail in the SmartFabric Storage Software Deployment Guide, but here are some highlights.
Our favorite topology is the dual-SAN topology with dedicated, air-gapped SAN switches. On the left is a small-scale version, with isolated SAN switches connecting hosts directly to the storage subsystem. On the right is a large-scale version with multiple arrays, an entire switch fabric for SAN A, and another separate fabric for SAN B.
Because Dell SmartFabric Services automates 99% of network deployment, storage engineers can deploy large switch fabrics without years of training and experience. Dell OpenManage Network Integration software provides a single portal for administering multiple SFSS and SFS instances.
It’s possible to use the same switches for application and NVMe/TCP storage traffic (we call this the converged topology), but we must plan carefully to prevent congestion spreading and Incast. After all, we don’t want anything to get in the way of true love!
The only way is up for NVMe/TCP. Ethernet speeds are increasing and becoming more affordable, and application developers will focus on software that can take full advantage of easier access to large amounts of data. We will see Dell and other vendors including TP-8009 and TP-8010 functionality in their products so that they may take part in the revolution.
For more help with planning your network for SFSS for NVMe/TCP, check out the Network Planning section in the SmartFabric Storage Software Deployment Guide.
Keep an eye out for new compatible endpoints appearing on the Dell Networking Support & Interoperability Matrix.
If you’d like to try configuring SFSS for yourself, take our Interactive Demo for a test drive!
Happy Valentine’s Day 2022!
Resources
- SmartFabric Storage Software on InfoHub (Deployment Guide, White Paper, Videos, Support & Interoperability Matrix)
- SmartFabric Storage Software on Dell Support (User Guide, Troubleshooting Guide, API Guide, Release Notes, Security Configuration Guide)
- Interactive Demo
- SFSS on Dell Technologies (Solution Brief, Top 5 Reasons, Spec Sheet)
Special thanks to Erik Smith, Heather Morgan, and Alex Loy.