Migrating VM from one subscriptoin to another

Question

For the migration of the domain joined VM from one subscription to another is it better to move with the ASR or take disk snapshot move the disk snapshot copy to another subscription and attach OS and data disk to new VM after shutting down previous VM to avoid computer account conflicts.

Answer 1

Hi @prasantc ,

When migrating a domain-joined virtual machine (VM) from one Azure subscription to another, both Azure Site Recovery (ASR) and the disk snapshot method have their advantages and considerations. The choice between them depends on various factors, including your specific requirements, cost considerations, and the complexity of the migration. Here's a comparison to help you decide:

 

Azure Site Recovery (ASR):

Advantages:

·       Live Migration: ASR allows you to perform live migrations, minimizing downtime during the migration process.

·       Replication: ASR replicates your VMs to the target Azure region, making it relatively easy to failover to the new region if needed.

·       Change Tracking: ASR tracks changes on the source VM during replication, ensuring that the destination VM is up to date.

·       Simplified Failback: In case you need to revert to the source subscription, ASR provides a more straightforward failback process.

Considerations:

·       Cost: ASR has associated costs for replication and recovery. You should consider the cost implications, especially for long-term use.

·       Complexity: ASR configuration can be complex, and it may require you to set up a recovery services vault, configure replication policies, and manage failover and failback processes.

Disk Snapshot and Manual Migration:

Advantages:

·       Lower Initial Cost: Creating snapshots and copying disks may have lower initial costs compared to ASR.

·       Control: You have more control over the migration process and can schedule it at your convenience.

Considerations:

·       Downtime: Using snapshots and copying disks typically involves VM downtime during the migration process, as you need to shut down the source VM.

·       Manual Process: It's a more manual and potentially error-prone process. You'll need to ensure the VM configuration, networking, and domain membership are correctly set up in the target subscription.

·       Computer Account Conflicts: As you mentioned, you'll need to address potential computer account conflicts by resetting the machine password in Active Directory.

Recommendation:

1.      If minimizing downtime is a critical consideration, and you can tolerate the associated costs, ASR is the better option. ASR provides a more automated and streamlined process for migrating VMs while maintaining live operation.

2.      If cost is a primary concern, and you can accept downtime during the migration, the disk snapshot and manual migration method may be more cost-effective, but it requires more manual effort.

3.      Be aware that regardless of the method chosen, you'll need to address domain membership and Active Directory-related issues to ensure the VM functions correctly in the new subscription.

4.      Your choice depends on your specific needs, budget, and comfort level with the migration process. It's a good practice to thoroughly plan and test your migration strategy before executing it in a production environment.