The following recommendations apply to dual site (Site A/Site B) and multiple-site (Site A/Site B/Site C) NSX-T Data Center deployments.

Dual Site Requirements and Recommendations

Note: Starting from NSX-T Data Center v3.0.2 onwards, VMware Site Recovery Manager (SRM) is supported.
  • Do not deploy NSX Managers in a dual-site scenario without vSphere HA or VMware SRM. In this scenario, one site requires the deployment of two NSX Managers and the loss of that site will impact the operation of NSX-T Data Center.
  • Deployment of NSX Managers in a dual site scenario with vSphere HA or VMware SRM can be done with the following considerations:
    • A single stretched vSphere cluster contains all the hosts for NSX Managers.
    • All three NSX Managers are deployed to a common management subnet/VLAN to allow IP address preservation upon recovery of a lost NSX Managers.
    • For latency between sites, see the storage product requirements.
Scenario example:
  • A vSphere cluster in which all three NSX Managers are deployed.
  • The vSphere cluster consists of six or more hosts, with three hosts in Site A and three hosts in Site B.
  • The three NSX Managers are deployed to distinct hosts with additional hosts for placement of recovered NSX Managers:
    Site A:
    • Host-01 with nsxmgr-01 deployed
    • Host-02 with nsxmgr-02 deployed
    • Host-03 with nsxmgr-03 deployed
    Site B:
    • Host-04 with no NSX Manager deployed
    • Host-05 with no NSX Manager deployed
    • Host-06 with no NSX Manager deployed
  • vSphere HA or VMware SRM is configured to recover any lost NSX Manager (e.g., nsxmgr-01) from any host (e.g., Host-01) in Site A to one of the hosts in Site B.
Thus, upon failure of Site A, vSphere HA or VMware SRM will recover all NSX Managers to hosts in site B.
Important: You must properly configure anti-affinity rules to prevent NSX Managers from being recovered to the same common host.

Multiple (Three or More) Site Requirements and Recommendations

In a scenario with three or more sites, you can deploy NSX Managers with or without vSphere HA or VMware SRM.

If you deploy without vSphere HA or VMware SRM:
  • It is recommended that you use separate management subnets or VLANs per site.
  • Maximum latency between NSX Managers is 10ms.
Scenario example (three sites):
  • Three separate vSphere clusters, one per site.
  • At least one host per site running NSX Manager:
    • Host-01 with nsxmgr-01 deployed
    • Host-02 with nsxmgr-02 deployed
    • Host-03 with nsxmgr-03 deployed
Failure scenarios:
  • Single site failure: Two remaining NSX Managers in other sites continue to operate. NSX-T Data Center is in a degraded state but still operational. It is recommended you manually deploy a third NSX Manager to replace the lost cluster member.
  • Two site failure: Loss of quorum and therefore impact to NSX-T Data Center operations.

Recovery of NSX Managers may take as long as 20 minutes depending on environmental conditions such as CPU speed, disk performance, and other deployment factors.