HA and DR Storage on Azure: A Great Overview
As we begin or continue our journey to using cloud as a part of our infrastructure, it is very important to understand the architecture of storage environments in the cloud. Microsoft Azure has a number of options, and luckily there are some great resources to help us make the decision on how to design and build our High Availability (HA) and Disaster Recovery (DR) options on Azure storage.
Local Versus Geo-Redundant
One of the more confused topics in enterprise architecture is the difference between HA and DR. HA provides locally redundant storage which is shared among front-end resources to ensure availability in the event of one of the local storage nodes. HA is also assumed to be used for live maintenance without having to take down the overall environment. In other words, we are usually dealing with planned situations.
For DR, we have to use a bigger plan which is that we may have a total, unexpected site loss on the local environment which requires a geo-redundant storage option for us to have geographically dispersed copies of our content to recover to a secondary site.
This article by Yung Chou from Microsoft does a superb job of explaining the Microsoft Azure storage services related to HA and DR.