Migration of SQL VMs to Azure SQL Managed Instance

Question

Migration of SQL VMs to Azure SQL Managed Instance

InfraSolutions 711

Hello,

We have an infrastructure setup in Azure that includes SQL instances. There are 2 SQL Server VMs available, enabled with Failover Cluster Instances (FCI), and they share the same data disk. For backup, we use Blob Storage with Geo-Redundant Storage (GRS) enabled.

We are planning to migrate the SQL VMs to Azure SQL Managed Instance. We referred to this migration guide and understand that Microsoft recommends the following options:

Log Replay Service (LRS)
Azure SQL migration extension for Azure Data Studio - migration with near-zero downtime.
Native RESTORE DATABASE FROM URL - uses native backups from SQL Server and requires some downtime.

Since we want to migrate all databases to SQL Managed Instance with minimal downtime, it seems that the Azure SQL migration extension for Azure Data Studio may fit our requirements best, as it provides an interactive interface for managing the migration. However, the Log Replay Service also offers minimal downtime but may require manual orchestration, with progress monitored using PowerShell or Azure CLI.

For a smooth migration, I would like to understand the architectural workflow. We found this architecture link. Could you please confirm if I'm referring to the correct link for implementation?

Moreover, during this migration, restoring data from the shared data disk to the SQL Managed Instance is still feasible. However, the recommendation is to use Blob Storage for restoring up-to-date databases to the SQL Managed Instance. Is my understanding correct?

Also, can you suggest any recommendations?

Prasad Chaganti 770 Reputation points Microsoft External Staff Moderator

2025-03-18T20:32:26.1366667+00:00

Hi MJ-1983,

Your understanding of the migration options and the recommendation to use Blob Storage for restoring up-to-date databases to the SQL Managed Instance is correct.

For the architectural workflow, you can refer to the following Documents:

https://learn.microsoft.com/en-us/azure/azure-sql/managed-instance/log-replay-service-migrate?view=azuresql&tabs=sas-token

https://learn.microsoft.com/en-us/azure/azure-sql/managed-instance/log-replay-service-overview?view=azuresql

Make sure your backups are stored in Azure Blob Storage with Geo-Redundant Storage (GRS) for high availability and disaster recovery.

Use the RESTORE DATABASE FROM URL method to restore backups to the SQL Managed Instance.

Monitor the migration progress using PowerShell or Azure CLI with Log Replay Service (LRS).

Test the migration process in a development environment before doing it in production to catch any issues early.

Check that the network connectivity between the source and target servers is set up correctly to avoid disruptions during the migration.

I hope this information helps. Please do let us know if you have any further queries.
InfraSolutions 711 Reputation points

2025-03-18T21:09:25.4766667+00:00

Thank you so much for your response. I went through the links you provided and learned that they refer to LRS. Is LRS the easiest way to migrate SQL VMs hosted in Azure to Azure SQL Managed Instance? The reason I’m asking is that I read an article stating that monitoring the operation's progress is entirely manual, with no interface to understand where we are in the migration process. Is that correct?

For a seamless migration, is LRS the recommended approach?

I came across another link where the architecture of the Azure Database Migration Service is explained differently, including a combination of LRS, DMS, and Azure Data Studio, as shown in the diagram below,
Prasad Chaganti 770 Reputation points Microsoft External Staff Moderator

2025-03-19T17:45:45.8833333+00:00

Hi MJ-1983,

LRS is one of the recommended options for migrating SQL VMs to Azure SQL Managed Instance (MI) with minimal downtime. However, LRS does require manual monitoring using PowerShell or Azure CLI, as there's no direct graphical interface for tracking the progress.

Azure SQL migration extension for Azure Data Studio is often considered more user-friendly since it provides an interactive interface for monitoring and managing the migration. It also supports near-zero downtime, making it suitable for seamless migrations.

If ease of tracking and monitoring is a priority, Azure SQL migration extension for Azure Data Studio would be more suitable since it provides better visibility and control.

If you prefer more flexibility and control over the migration steps, LRS is still a solid option, but it will require manual orchestration using PowerShell or CLI.

The combination of DMS (Database Migration Service) and LRS allows for more automation and streamlined management, as seen in the architecture diagram you referred to. This approach can balance automation with granular control.

For minimal downtime and better tracking, using the Azure SQL migration extension combined with DMS could be the most effective path.

I hope this information helps. Please do let us know if you have any further queries.
InfraSolutions 711 Reputation points

2025-03-20T16:43:43.8133333+00:00

Thank you very much for the clarification. As per my understanding, LRS and the Azure SQL Migration Extension for Azure Data Studio are free, while DMS incurs additional costs. I hope this is correct.

We plan to migrate all our databases to SQL MI, so we prefer using DMS (fully managed/automated). Would the downtime for DMS be longer than LRS?

Also, sorry to double-check, but in this case, would Option A be the right choice for our migration? (Assuming setup consists of a SQL Server with FCI enabled, sharing the same data disk, and performing data backups to a storage location (Blob).)
InfraSolutions 711 Reputation points

2025-03-21T09:22:01.5933333+00:00

That's fantastic! I think you have clarified all my high-level questions. I really appreciate your time on this.
Prasad Chaganti 770 Reputation points Microsoft External Staff Moderator

2025-03-21T22:08:50.1433333+00:00

Hi MJ-1983,

Just checking in to see if the below answer helped. If this answers your query, do click Accept Answer and Yes for was this answer helpful. And, if you have any further query do let us know.

Accepted answer

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Your answer

Prasad Chaganti 770 Reputation points Microsoft External Staff Moderator

2025-03-18T20:32:26.1366667+00:00

Hi MJ-1983,

Your understanding of the migration options and the recommendation to use Blob Storage for restoring up-to-date databases to the SQL Managed Instance is correct.

For the architectural workflow, you can refer to the following Documents:

https://learn.microsoft.com/en-us/azure/azure-sql/managed-instance/log-replay-service-migrate?view=azuresql&tabs=sas-token

https://learn.microsoft.com/en-us/azure/azure-sql/managed-instance/log-replay-service-overview?view=azuresql

Make sure your backups are stored in Azure Blob Storage with Geo-Redundant Storage (GRS) for high availability and disaster recovery.

Use the RESTORE DATABASE FROM URL method to restore backups to the SQL Managed Instance.

Monitor the migration progress using PowerShell or Azure CLI with Log Replay Service (LRS).

Test the migration process in a development environment before doing it in production to catch any issues early.

Check that the network connectivity between the source and target servers is set up correctly to avoid disruptions during the migration.

I hope this information helps. Please do let us know if you have any further queries.
InfraSolutions 711 Reputation points

2025-03-18T21:09:25.4766667+00:00

Thank you so much for your response. I went through the links you provided and learned that they refer to LRS. Is LRS the easiest way to migrate SQL VMs hosted in Azure to Azure SQL Managed Instance? The reason I’m asking is that I read an article stating that monitoring the operation's progress is entirely manual, with no interface to understand where we are in the migration process. Is that correct?

For a seamless migration, is LRS the recommended approach?

I came across another link where the architecture of the Azure Database Migration Service is explained differently, including a combination of LRS, DMS, and Azure Data Studio, as shown in the diagram below,
Prasad Chaganti 770 Reputation points Microsoft External Staff Moderator

2025-03-19T17:45:45.8833333+00:00

Hi MJ-1983,

LRS is one of the recommended options for migrating SQL VMs to Azure SQL Managed Instance (MI) with minimal downtime. However, LRS does require manual monitoring using PowerShell or Azure CLI, as there's no direct graphical interface for tracking the progress.

Azure SQL migration extension for Azure Data Studio is often considered more user-friendly since it provides an interactive interface for monitoring and managing the migration. It also supports near-zero downtime, making it suitable for seamless migrations.

If ease of tracking and monitoring is a priority, Azure SQL migration extension for Azure Data Studio would be more suitable since it provides better visibility and control.

If you prefer more flexibility and control over the migration steps, LRS is still a solid option, but it will require manual orchestration using PowerShell or CLI.

The combination of DMS (Database Migration Service) and LRS allows for more automation and streamlined management, as seen in the architecture diagram you referred to. This approach can balance automation with granular control.

For minimal downtime and better tracking, using the Azure SQL migration extension combined with DMS could be the most effective path.

I hope this information helps. Please do let us know if you have any further queries.
InfraSolutions 711 Reputation points

2025-03-20T16:43:43.8133333+00:00

Thank you very much for the clarification. As per my understanding, LRS and the Azure SQL Migration Extension for Azure Data Studio are free, while DMS incurs additional costs. I hope this is correct.

We plan to migrate all our databases to SQL MI, so we prefer using DMS (fully managed/automated). Would the downtime for DMS be longer than LRS?

Also, sorry to double-check, but in this case, would Option A be the right choice for our migration? (Assuming setup consists of a SQL Server with FCI enabled, sharing the same data disk, and performing data backups to a storage location (Blob).)
InfraSolutions 711 Reputation points

2025-03-21T09:22:01.5933333+00:00

That's fantastic! I think you have clarified all my high-level questions. I really appreciate your time on this.
Prasad Chaganti 770 Reputation points Microsoft External Staff Moderator

2025-03-21T22:08:50.1433333+00:00

Hi MJ-1983,

Just checking in to see if the below answer helped. If this answers your query, do click Accept Answer and Yes for was this answer helpful. And, if you have any further query do let us know.

Answer 1

Hi MJ-1983,

LRS and the Azure SQL Migration Extension for Azure Data Studio are free.

Database Migration Service (DMS) does incur costs, but it provides a fully managed and automated migration experience, which may justify the cost depending on the complexity and downtime requirements.

Downtime Comparison:

LRS offers minimal downtime, but since it requires manual orchestration using PowerShell or Azure CLI, the complexity could lead to increased operational overhead.

DMS is designed for automated and more controlled migration with downtime minimized, but the overall downtime depends on the size of the database and network throughput. In most cases, DMS can offer better control over downtime compared to LRS due to its automated nature.

Option A is the correct approach in your scenario:

Since your setup includes SQL Server Failover Cluster Instances (FCI) sharing the same data disk and performing backups to Azure Blob Storage, Option A (migration from Azure Blob Storage) is well-suited.

Using DMS with Option A will allow automated migration from backups stored in Azure Blob, ensuring minimal downtime and high availability.

If you prefer a hands-off, automated migration with controlled downtime, DMS with Option A is the most suitable path.

Test the process in a lower environment first to validate the setup and monitor the migration time.

If cost is a concern and you can manage manual orchestration, LRS combined with the Azure SQL Migration Extension remains a valid alternative.

Hope this helps. Do let us know if you any further queries.

If this answers your query, do click Accept Answer and Yes for was this answer helpful. And, if you have any further query do let us know.
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Migration of SQL VMs to Azure SQL Managed Instance

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