Problem Statement
In a VMware vSphere environment using Virtual Distributed Switches (VDS) where all VMs including vCenter is hosted on the VDS, What is the most suitable Port Binding setting for dvPortgroups to ensure maximum performance and availability?
Assumptions
1. Enterprise Plus Licensing
2. vCenter is hosted on the VDS
Requirements
1. The environment must have central management of vNetworking
2. All VMs must be able to be powered on in the event of a vCenter outage
3. Network connectivity must not be impacted if vCenter is down.
Motivation
1. Reduce complexity where possible.
2. Maximize the availability of the infrastructure
Architectural Decision
Use the default dvPortGroup Port Binding setting of “Static Binding”
Justification
1. A dvPortGroup port is assigned to a VM and reserved when a VM is connected to the dvPortGroup. This ensures connectivity at all times including when vCenter is down.
3. Using “Static Binding” ensures the vCenter VM can be powered on and connected to the dvPortGroup even after a failure/outage.
4. “Static Binding” is the default setting and there is no reason to modify this setting.
Implications
1. The number of VMs supported on the dvPortGroup / VDS is limited to the number ports on the VDS (not overcommitment of ports is possible).
2. Number of ports configured on a dvPortGroup should be greater than the maximum number of VMs required to be supported.
3. Port Allocation should be left at the default of “Elastic” to ensure the number of ports is automatically expanded if/when required.
4. New Virtual machines cannot be powered on and connected to a dvPortGroup (VDS) when vCenter is down.
Alternatives
1. Set dvPortGroup Port Binding to “Dynamic binding”
2. Set dvPortGroup Port Binding to “Ephemeral binding”
Related Articles
1. Distributed vSwitches and vCenter outage, what’s the deal? – @duncanyb (VCDX #007)