While at PASS Summit 2019, I gave a session on designing Azure Disaster Recovery Strategies for the Data Platform. In that session, I talked about Azure storage and the various redundancy options that are available to the storage, one of them being geo-redundant (GRS).
Geo-redundant storage asynchronously replicates your data from one region to another providing up to 16 9’ (that’s 99.99999999999999) of redundancy per year. 9-9’s is 31.56 milliseconds of downtime in a given year, therefore geo-redundant Azure storage is architected to have less than 30 milliseconds of downtime. That high level of redundancy allows you to have a lot of confidence that in the event of a disaster your data is safe and secure hundreds of miles away from your primary region.