An enterprise is designing a disaster recovery (DR) solution using Azure Site Recovery (AS… — Microsoft Azure Solutions Architect (AZ-305)

An enterprise is designing a disaster recovery (DR) solution using Azure Site Recovery (ASR) to replicate workloads from the East US region to the West US region. The target Recovery Point Objective (RPO) is 2 hours, and the Recovery Time Objective (RTO) is 4 hours.

The infrastructure consists of four virtual machines (VMs) using Premium SSD storage. The write churn metrics for each VM are detailed in the table below:

Virtual Machine	Disk Churn Details	Total VM Churn
VM1 (Web Server)	Disk 1: $5\text{ MB/s}$ , Disk 2: $8\text{ MB/s}$	$13\text{ MB/s}$
VM2 (Database Server)	Disk 1: $45\text{ MB/s}$ , Disk 2: $48\text{ MB/s}$	$93\text{ MB/s}$
VM3 (App Server)	Disk 1: $60\text{ MB/s}$	$60\text{ MB/s}$
VM4 (Analytics Server)	Disk 1: $15\text{ MB/s}$ , Disk 2: $20\text{ MB/s}$ , Disk 3: $10\text{ MB/s}$	$45\text{ MB/s}$

Which of the following virtual machines can be successfully replicated to the target region using the Standard replication tier of Azure Site Recovery?

VM1 (Web Server)Answer
B
VM2 (Database Server)
C
VM3 (App Server)
VM4 (Analytics Server)Answer

Answer

VM1 (Web Server) and VM4 (Analytics Server) can be successfully replicated using the Standard replication tier of Azure Site Recovery.

VM1 and VM4 are correct because they satisfy the Azure Site Recovery Standard replication tier constraints: the maximum write churn per Premium SSD disk is less than or equal to

54\text{ MB/s}

and the total write churn per VM is less than or equal to

80\text{ MB/s}

. Specifically, VM1 has a maximum disk churn of

8\text{ MB/s}

(with a total of

13\text{ MB/s}

) and VM4 has a maximum disk churn of

20\text{ MB/s}

(with a total of

45\text{ MB/s}

Step-by-Step Solution

Identify the limits of the Standard replication tier of Azure Site Recovery (ASR) for Azure VMs.

The limits for Standard ASR are

54\text{ MB/s}

write churn per Premium SSD disk and

80\text{ MB/s}

total write churn per virtual machine.

These limits dictate which VM workloads can be replicated without experiencing replication failures or requiring the High-Churn tier.

Evaluate the disk-level and VM-level churn for each virtual machine against the ASR Standard tier limits.

VM1 (max disk

8\text{ MB/s}

, total

13\text{ MB/s}

) is within limits. VM2 (max disk

48\text{ MB/s}

, total

93\text{ MB/s}

) violates the VM-level limit of

80\text{ MB/s}

. VM3 (max disk

60\text{ MB/s}

, total

60\text{ MB/s}

) violates the disk-level limit of

54\text{ MB/s}

. VM4 (max disk

20\text{ MB/s}

, total

45\text{ MB/s}

) is within limits.

This step determines which specific VMs exceed either the individual disk threshold or the aggregate VM threshold.

Select the compliant virtual machines.

VM1 (Web Server) and VM4 (Analytics Server) are the only virtual machines that satisfy both constraints.

Only virtual machines satisfying both disk and VM-level limits are supported under the Standard ASR replication tier.

Key Concept

Azure Site Recovery VM replication limit validation

Question

Answer

Step-by-Step Solution

Key Concept

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