Migrate On-prem SQL Server databases to Azure SQL Database

Question

Here is the scenario:

• On-premises SQL Server (2-Node Cluster) has around 40 databases
• Preparing to migrate all 40 databases to Azure SQL Database

Quick Qs:

1. In Azure, all 40 databases need to be migrated under 1 Azure SQL Server. Is it feasible?
2. I understand that each Azure SQL Database requires to select the model/capacity etc. But, Is it for every Azure SQL Database requires a separate SQL License? i.e., 40 databases require 40 SQL Licenses? because we wanted all the 40 databases to be migrated as "Azure SQL Database" under a single Azure SQL Server. Please clarify.
3. At On-premises, 40 databases (all together 2 TB size, database sizes vary from 2 GB to 700 GB) running in a single SQL server and if we choose Azure SQL Database as an option , Isn't it too costly? if not, please clarify with details.

I sincerely request the forum experts to provide clarifications at the earliest.

Answer 1

Let me try to answer your questions:

Answer for Question 1: You can migrate all of the databases to a logical Azure SQL server using Azure Database Migration Service as explained on this tutorial. But before you try to migrate them perform an assessment first as mentioned on the tutorial.

Answer for Question 2: If you migrate them to Azure SQL DTU model, no license fees are paid. DTU model does not have licensing costs.

Answer for Question 3: You can use DMA tool to help you assess the recommended SKU for each database and then use Azure SQL pricing web site to estimate monthly costs. Make use of Azure SQL reservations to save money as explained here. You can also scale down resources during non-business hours to save money even further.

Answer 2

Here are my answers:

1. In Azure SQL Database, a "server" is only a logical container that permits you define logins etc. Each database is still its own service. But, yes, having all databases on the same server is feasible.
2. As long as you go for Azure SQL Database or Azure Managed Instance, the license is included in the platform. If you end up with using an Azure VM, you need a license. It can be included in the VM price, or you can use BYOL (Bring Your Own License.)
3. As for pricing, it is a matter of the length of the string. There are umpteen service levels for Azure SQL Database, and you can easily spend a lot of money if you pull all levers to the far right.

You need to be aware of that Azure SQL Database does not exactly have the same surface area as on-prem. You may find that more than one of your database use functionality that is not supported in Azure SQL Database.

Answer 3

First you should clarify what exactly you are looking/planing to move to.

Azure SQL Database" under a single Azure SQL Server.

A Azure SQL Database is really one separate database, not a server with several databases, as you know from on-premise.

The there is an offer about "Azure SQL Managed Instance", which equal on-premise.

Or you can run a VM on Azure with an installed SQL Server.

Answer 4

there are multiple sql hosting options in azure.

you can host a vm and sqlserver, so it just like on prem. this would be the same licensing costs

you can host sqlserver in a docker image. this would be linux licensing.

azure sqlserver. a cloud managed sql database. no license, only running costs.

for low volume databases, you should look at the serverless sql database:

[https://learn.microsoft.com/en-us/azure/azure-sql/database/serverless-tier-overview?view=azuresql