ASR - Disaster Recovery and HA

 

Azure Site Recovery solution has a low Recovery point objective(RPO) & Recovery Time Objective(RTO) if there is a need to failover, RPO & RTO could be pretty high when using traditional back-up strategies.

 Also, we get High availability when using Azure Site Recovery(ASR)

 DR copy can be behind by  minutes as compared to the Primary region when using Azure Site Recovery.

 ASR allows a 'Test-Failover' to be performed if needed for testing the RTO and RPO

We configure DR for our VMs where they are replicated to some other region for eg. East is primary and West is secondary

Make sure RTO and RPO is minimum

We also perform DR drills to prepare and assess if we are able to make the VMs online within the defined SLA

Test Failover is performed to test the above

Before you fail over, check that:

The VM is running a supported Windows or Linux operating system.

The VM complies with compute, storage, and networking requirements.

Some important points to remember before you proceed with enabling the replication in ASR

1. Public IP address of the production application cannot be retained on failover. Workloads brought up as part of failover process must be assigned an Azure Public IP resource available in the target region. This step can be done either manually or is automated with recovery plans.
2. ONLY THE PRIVATE IP is RETAINED OR if that IP is not available, then the next IP in the subnet is allotted.
3. HOSTNAME is also RETAINED as is.