What is the benifit of using one or multiple VDS (Virtual Distributed Switch) per cluster? What value do each approach bring? And what tasks can each approach solve? Lets discuss it in more detail, because this can be a very tricky desicision and in my practice i faced with it already multiple times.
Using one VDS per vCenter for all clusters
Decision:
Signle VDS per workload domain with multiple clusters in one vCenter
Justification:
- Uniform and identical configuration across whole workload domain and all clusters
- Convenience and easy management, as well as keeping the configuration up to date for all specific use cases
- Simlification from integration perspective. External solutions, like AVI (NSX Adv LB) or F5, that need to be integrated with vSphere/vCenter will discover only one port-group that is stratched between all clusters in workload instead on multiple (if it will be multiple its really hard to discover what port-group should be used for VMs provisioning and port-binding)
Impact:
- Inflexibility of configuration in the case of heterogeneous servers in different virtualization clusters. Each server types can have different number of ports/uplinks and could have differen connections to underlying infrastructure
Using multiple VDS per vCenter for each cluster
Decision:
Multiple VDS per workload domain with multiple clusters in one vCenter. Each cluster has its own VDS
Justification:
- Flexible configuration. Ablity to adopt most of the needs and configuration to different types of servers in each cluster
- Independent configuration of each cluster, separation of management failure domain
- Ability to create granular NIOC policies for each cluster based on its type/enviroment/purpose
Impact:
- Hard to manage and provision configuration. External automation is needed to overcome this limitation
- Uncommon problems that are related to the integration with external/3rd party problems that can threat each port-group/configuration on different VDS and separate one, even if its uses same VLAN/Overlay segment.
To summarized there is no best solution what to choose, each option could be used in different cases in order to maximum satisfy for certain type of requirements in customer enviroment. Need to choose the best one!