Availability zones and regions have different purposes. Availability zones protect against failures of individual hosts. Regions provide disaster recovery of the entire SDDC.

Availability zones

An availability zone is the fault domain of the SDDC. Multiple availability zones can provide continuous availability of an SDDC, minimize down time of services and improve SLAs.


Regions provide disaster recovery across different SDDC instances. This design uses two regions. Each region is a separate SDDC instance. The regions have a similar physical layer and virtual infrastructure designs but different naming.

The identifiers follow United Nations Code for Trade and Transport Locations(UN/LOCODE) and also contain a numeric instance ID.


Availability Zone and Region Identifier

Region-Specific Domain Name

Region Description




San Francisco, CA, USA based data center


Region identifiers might vary according to the locations used in your deployment.

Table 1. Availability Zones and Regions Design Decisions

Decision ID

Design Decision

Design Justification

Design Implication


Use a single region.

Supports the reduced footprint requested for use in a consolidated SDDC.

Results in dual region being limited to backup/restore as there is no additional region to fail over to.


Deploy a single availability zone that can support all SDDC management components and compute workloads.

A single availability zone can support all SDDC management and compute components for a region.

The single availability zone can become a single point of failure and prevent high-availability design solutions. Results in limited redundancy of the overall solution.