As the growth and adoption of Virtual SAN continues to expand in enterprise data centers, the demand for designs and deployments across routed (L3) networks has increased. One of the fundamental components of the software-defined data center is Virtual SAN designs and deployments which must adhere to the same requirements and demands as the other software-defined data center components.
Designing an implementation of Virtual SAN across layer 3 networks require adequate planning and understanding of both the scalable capabilities of Virtual SAN and the network infrastructure, in order to be designed and implemented in the most flexible, efficient way in real scale-out fashion.
Virtual SAN extends upon the software-defined datacenter concept by pooling together distributed resources (storage devices) and manage them as a single entity (one datastore), this is achieved with the dependency of suitable network infrastructures to provide seamless inter-connectivity between the Virtual SAN cluster nodes.
When developing enterprise grade, Hyper-converged Infrastructure designs for Virtual SAN capable of supporting the deployments of similar component (hosts) it is critical to have a network infrastructure that can meet the connectivity requirements and be able to provide interconnectivity up to 100,000’s of hosts. At the time the network infrastructure must be flexible and have the ability to support the move of Virtual SAN cluster components whenever necessary.
Imagine pulling down a network harness to connect the nodes
Visualize the statement above as having a network harness installed in every rack where you can just pull it down and attach the Virtual SAN hosts. This would need to be the type of network that is high-performing, predictable, massively scalable and resilient enough to support storage traffic together with all the other traffic in the SDDC.
This year for VMworld, I teamed up with Brocade to develop a validated and tested design and deployment recommendation guide for Virtual SAN across vast and scalable routed network infrastructures powered by Brocade networking devices.
Brocade’s IP Fabric architecture, which can significantly scale within and across multiple Data Centers, has been well received in the industry for its automated and seamless operability. Brocade provides a leaf-spine architecture where servers attach to leafs that are interconnected via spines delivering a deterministic, high performing scale-out network.. The traffic between leafs and spines are based on an L3 IP underlay – leveraging Equal Cost Multi-pathing to utilize all available links and BGP to provide the routing. Relatively straight forward right? – Yeah! If you are a network expert!
Validated deployment of Virtual SAN on Brocade IP Fabric
We decided to validate and provide a recommended design for configuration of this type of architecture and built a network to demonstrate a Virtual SAN deployment over a truly routed network infrastructure across 5 data center racks, in each rack a pair of leaf switches are place Top of Rack (ToRs) – interconnecting the racks with two spine switches, illustrated in the diagram:
The Virtual SAN design has been architected to run natively on an L3 routed network and configured with high availability across racks with the use of Virtual SAN Fault Domains to prevent service outages or data access in the event of a rack failure. With five racks (5 Virtual SAN Fault Domains) the number of simultaneous rack failures the Virtual SAN infrastructure can tolerate is two (2N+1 formula).
Furthermore, all racks are interconnected via the IP Fabric in the same way and don’t need to be on adjacent floor tiles, not even in the same DC room! And on scalability, even by just adding more racks to above diagram goes to 850+ servers. That’s what I call flexibility, scalability & consistency!
Learn more about Virtual SAN design and ask the experts
Based on our validation of the solution we wrote a white paper on what to consider when designing and how we did the deployment. Be sure to stop by Brocade booth at VMworld and get a live demonstration of everything and tap into our experience with Virtual SAN design and deployment on layer 3 networks.
I want to thank Brocade along with Marcus Thordal, and Nikola Kjeldsen both from Brocade for all their work and participation in our joint venture.
To learn more about Brocade Data Center Fabrics and their activities at VMworld please visit the links below:
For future updates on Virtual SAN (VSAN), vSphere Virtual Volumes (VVol) and other Storage and Availability technologies, as well as vSphere Integrated OpenStack (VIO), and Cloud-Native Applications (CNA) be sure to follow me on Twitter: @PunchingClouds.