One influencing factor is that you can only create one dvPortgroup for VXLAN transport per VDS. So often you might want to treat this differently across clusters - e.g.(in production) LACP for compute clusters then active/standby failover for the Edge cluster. There's some good coverage in the NSX-v design guide around this. So as a starting point it gives you some flexibility as to how you treat that portgroup if you have more than one VDS. Another aspect could be if you need to run your VXLAN transport over L3 and therefore want to use a different VLAN tag on the portgroup for different sets of hosts. In a lab there possibly isn't going to be much in it depending on how deep you want your testing to go...
So what you are basically saying is:
- For a lab purpose it does not matter I can go both ways
- Using two Distributed Switches brings in more flexibility
- one VXLAN transport group for VXLAN per Distributed Switches
- there could be a scenario where you want to treat the VXLAN redundancy properties differently (flexibility)
Hi - yes that's pretty much it. There are some other considerations in production like if you want to restrict the span of external VLANs to your Edge cluster for instance (pretty typical design) you might want a separate VDS to the compute one and only create the VLAN-backed dvPortgroups on the Edge cluster VDS. Other reasons seem to largely be around logical/administrative separation like if you want to permission the VDSs differently for different users.
Take a look at page 77 in this:
Just to be clear - you can add multiple VDS into the same NSX Transport Zone and span a Logical Switch across all the attached hosts. The thing is that you can only create one dvPortgroup per VDS for VXLAN/VTEPs. L3 separation of VTEPs doesn't necessarily mandate a separate VDS for each segment as (covered in the guide above) perhaps you'd use global VLAN IDs in a production design. I'd say most of the reasons for splitting it would be outside of setting up a basic lab but at the same time it wouldn't hurt you if you wanted a simulated production design.