Best practices checklist for AZURE DR implementation

Conduct a risk assessment for each application, because each can have different requirements. Some applications are more critical than others and would justify the extra cost to architect them for disaster recovery.

Higher Agility

Define the RTO and RPO for each application.

• The RTO refers to the targeted amount of time determined by the business that is needed to be back up and running after a disaster or disruption happened. The more the application is critical, the lower the RTO should be.
  
  
•     The RPO refers to a point in time that is the acceptable amount of lost data due to the recovery.

Design for failure, starting with the application architecture.

Implement best practices for high availability, while balancing cost, complexity, and risk:

Implement disaster recovery plans and processes.

Consider failures that span the module level all the way to a complete cloud outage;

Establish backup strategies for all reference and transactional data; and

Choose a multi-site disaster recovery architecture.

Define a specific owner for disaster recovery processes, automation, and testing. The owner should manage and own the entire process.

Document the processes so they are easily repeatable. Although there is one owner, multiple people should be able to understand and follow the processes in an emergency.

Train the staff to implement the process.

Use regular disaster simulations for both training and validation of the process.

 

 

 

Business continuity and disaster recovery (BCDR): Azure Paired Regions

AZURE REGIONAL PAIRS
Geography	Regional pair A	Regional pair B
Asia-Pacific	East Asia (Hong Kong)	Southeast Asia (Singapore)
Australia	Australia East	Australia Southeast
Australia	Australia Central	Australia Central 2*
Brazil	Brazil South	South Central US
Brazil	Brazil Southeast*	Brazil South
Canada	Canada Central	Canada East
China	China North	China East
China	China North 2	China East 2
China	China North 3	China East 3*
Europe	North Europe (Ireland)	West Europe (Netherlands)
France	France Central	France South*
Germany	Germany West Central	Germany North*
India	Central India	South India
India	West India	South India
Japan	Japan East	Japan West
Korea	Korea Central	Korea South*
North America	East US	West US
North America	East US 2	Central US
North America	North Central US	South Central US
North America	West US 2	West Central US
North America	West US 3	East US
Norway	Norway East	Norway West*
South Africa	South Africa North	South Africa West*
Sweden	Sweden Central	Sweden South*
Switzerland	Switzerland North	Switzerland West*
UK	UK West	UK South
United Arab Emirates	UAE North	UAE Central*
US Department of Defense	US DoD East*	US DoD Central*
US Government	US Gov Arizona*	US Gov Texas*
US Government	US Gov Iowa*	US Gov Virginia*
US Government	US Gov Virginia*	US Gov Texas*

Understanding crash consistency and application consistency

 

In the context of snapshots, backups, and data protection in general, there are two types or states of data consistency:

•  Crash consistency - A backup or snapshot is crash consistent if all of the interrelated data components are as they were (write-order consistent) at the instant of the crash. To better understand this type of consistency, imagine the status of the data on your PC’s hard drive after a power outage or similar event. A crash-consistent backup is usually sufficient for nondatabase operating systems and applications like file servers, DHCP servers, print servers, and so on.

•  Application consistency - A backup or snapshot is application consistent if, in addition to being write-order consistent, running applications complete all their operations and flush their buffers to disk (application quiescing). Application-consistent backups are recommended for database operating systems and applications such as SQL, Oracle, and Exchange.

 

 

Reference Links:

https://docs.microsoft.com/en-us/azure/site-recovery/site-recovery-overview
https://docs.microsoft.com/en-us/azure/site-recovery/site-recovery-best-practices
https://docs.microsoft.com/en-us/azure/site-recovery/site-recovery-components
https://docs.microsoft.com/en-us/azure/availability-zones/cross-region-replication-azure