Virtual SAN and VMware NSX have been a topic of discussion in many of the customer meetings I participated in 2015 and already in 2016. Questions and concerns about compatibility and interoperability have been at the forefront of all of those discussions. I have noticed that there is a bit of confusion and misunderstanding with customers and also within the community in social media.
I’ve been leading some efforts at VMware around the use of Virtual SAN, and VMware NSX and different deployments scenarios around Layer-2 and Layer-3 network topologies, as well as stretched cluster use cases. Because of the experience I have gathered while working with both products, I can provide some definitive answers for some of the frequently asked customer questions. Hopefully, my answers will clarify some of the confusion and misunderstandings around Virtual SAN and VMware NSX compatibility and interoperability.
The number one question about the two products is “are Virtual SAN compatible with VMware NSX?” or vice versa. The quick and short answer is absolutely, and unequivocally yes!!!. But there is more to this question as well as the answer. The two products can be deploy and co-exist on the same vSphere infrastructure without any issues. It is paramount for everyone to understand that neither Virtual SAN nor VMware NSX is dependent on each other to deliver their functionalities, resources, and services.
I have found that whenever the question of compatibility is asked, it’s in the context of being able to place the Virtual SAN network traffic on the VXLAN overlay. From what I have observed, this is where some of the confusion stems from.
The answer is no! VMware NSX does not support the configuration of the Virtual SAN network traffic over the VXLAN overlay. It’s crucial for everyone asking this question to understands that this is not an incompatibility or interoperability issue but a position on the use and support of the VXLAN overlay by VMware NSX. This is not unique to Virtual SAN as it applies to any statically defined VMkernel interface traffic such as vMotion, iSCSI, NFS, FCoE, Management, etc.
Part of the reason for not supporting VMkernel traffic over the VXLAN overlay is primarily to avoid any circular dependency of having VMkernel infrastructure networks dependent on the VXLAN overlay they are there to support. The logical networks that are delivered in conjunction with the VXLAN overlay are to be used by transient types of virtual machines which require network mobility and flexibility.
The Virtual SAN network stack supports flexible deployments out-of-the-box, and it can be configured over layer-2 and layer-3 network topologies. The Virtual SAN network should be kept isolated and managed with the necessary networking technologies suitable for its deployment (IP Multicast, IGMP, IGMP Snooping, PIM) as recommended by VMware.
I hope my explanations are useful, and it clears up the misunderstandings around VMware Virtual SAN and VMware NSX compatibility and interoperability.
For future updates on Virtual SAN (VSAN), vSphere Virtual Volumes (vVols) 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.