When we talk about Availability Zones and Availability Sets we talk about high availability of our resources.
When we Create a Virtual Machines in Availability Sets it will increase the availability of your Applications on the other hand the Availability Zones allows you to deploy your VM’s into different data centers within the same region.
Various Azure services that supports Availability Zones –
- Linux Virtual Machines
- Windows Virtual Machines
- Virtual Machine Scale Sets
- Managed Disks
- Load Balancer
- Public IP address
- Zone-redundant storage
- SQL Database
- Event Hubs
- Service Bus (Premium Tier Only)
- VPN Gateway
- Application Gateway (preview)
If you are using an Availability Sets for your VM. Your VM would be spread across update and fault domains but it could happen that your Azure VM is running within the same building . So if something happens to that building in case of an outage your VM may go down. In order to avoid it you can deploy your VM’s to Availability Zones. In this case your VM’s are spread across different buildings but within same Azure Region ( picture depicted above ).
Service Level Agreement ( SLA ) for the above –
Currently Availability Zones is not available for all regions. It only supports –
- Central US
- East US
- East US 2
- France Central
- North Europe
- Southeast Asia
- West Europe
- West US
You can refer to the following link to know more about Availability Zones.