I want to use geo-zone-redundant storage, but I have data that we're legally bound to store only within the US. How can I set my storage account to have geo-redundant storage but specify which region the redundant storage is in? For example if my primary region is US East 1, I want to set my secondary redundant region to be US West 2 for example.
Paired regions are pre-defined by Microsoft and cannot be selected individually.
When you create a storage account, you select the primary region for the account. The paired secondary region is determined based on the primary region, and can't be changed. https://learn.microsoft.com/en-us/azure/storage/common/storage-redundancy#redundancy-in-a-secondary-region
You can find the regional pairs here: https://learn.microsoft.com/en-us/azure/availability-zones/cross-region-replication-azure#azure-cross-region-replication-pairings-for-all-geographies
For East US, the corresponding paired region would be West US.