Merge pull request #230298 from dlepow/patch-178

[APIM] Unit costs

Author: Jill Grant

articles/reliability/migrate-api-mgt.md

@@ -18,34 +18,7 @@ In this article, we'll take you through the different options for availability z
 
 ## Prerequisites
 
-* To configure API Management for zone redundancy, your instance must be in one of the following regions:
-    
-    * Australia East
-    * Brazil South
-    * Canada Central
-    * Central India
-    * Central US
-    * East Asia
-    * East US
-    * East US 2
-    * France Central
-    * Germany West Central
-    * Japan East
-    * Korea Central (*)
-    * North Europe
-    * Norway East
-    * South Africa North (*)
-    * South Central US
-    * Southeast Asia
-    * Switzerland North
-    * UAE North
-    * UK South
-    * West Europe
-    * West US 2
-    * West US 3
-
-    > [!IMPORTANT]
-    > The regions with * against them have restrictive access in an Azure subscription to enable availability zone support. Please work with your Microsoft sales or customer representative.
+* To configure API Management for zone redundancy, your instance must be in one of the Azure regions with [availability zone support](availability-zones-service-support.md#azure-regions-with-availability-zone-support).
 
 * If you haven't yet created an API Management service instance, see [Create an API Management service instance](../api-management/get-started-create-service-instance.md). Select the Premium service tier.
 
@@ -65,6 +38,8 @@ There are no downtime requirements for any of the migration options.
 
 * Migrating to availability zones or changing the availability zone configuration will trigger a public [IP address change](../api-management/api-management-howto-ip-addresses.md#changes-to-the-ip-addresses).
 
+* When enabling availability zones in a region, you configure a number of API Management scale [units](../api-management/upgrade-and-scale.md) that can be distributed evenly across the zones. For example, if you configure 2 zones, you could configure 2 units, 4 units, or another multiple of 2 units. Adding units incurs additional costs. For details, see [API Management pricing](https://azure.microsoft.com/pricing/details/api-management/).
+
 * If you've configured autoscaling for your API Management instance in the primary location, you might need to adjust your autoscale settings after enabling zone redundancy. The number of API Management units in autoscale rules and limits must be a multiple of the number of zones.
 
 ## Option 1: Migrate existing location of API Management instance, not injected in VNet