Written by our Senior Cloud Pre-Sales Engineer – Tom Button.
In this blog, we’ll take you through the major steps to a rehost or environmental modernisation in Azure for Windows Server & SQL Server migrations, including the assessment of your current on-premises environment, and ultimately performing said migration.
Before you migrate; plan, assess & prepare
As per the title of this section, ‘before you migrate; plan, assess & prepare’ – a cloud migration starts with careful planning, a phased approach to any execution and deployment of production workloads. Although the ease of entry to Azure, and the cloud in general, makes it tempting to jump straight in, an inadequate cloud architecture is a short-cut to preventing you and your customers from realising the benefits that prompted the desire to migrate from the offset.
Consider a cloud migration as a strategic undertaking, that must be executed without significantly impacting business operations, service delivery, performance, and data protection requirements. Which is why our Azure Practice crucially recommend that before execution, you complete a full assessment to determine what workloads your customer has, where they are installed, what dependencies they have, which are the best candidates for migration to Azure & ultimately what workloads should be considered comparable in Azure vs the on-premises set-up.
‘To provide an example as to why you would want to consider assessing your customers environment before executing on the deployment of production workloads, let’s take a Windows Server as an example. Naturally, partners and their customers when performing a rehost or modernisation migration will typically look to replicate what is currently hosted on-premises i.e., an 8 Core 32 GB RAM Windows Server. Now, although this ‘will’ work from a technical perspective, from a commercial perspective we can almost guarantee that that isn’t going to be cost-effective. Why? Because let’s say for arguments sake that the lifespan of a server is circa 5 years, the customer will require that newly installed server to be suitable in size for not only today, but also at the end of that 5-year period [accounting for any organisational growth/expansion during that 5-year period]. With Azure – this isn’t required, as you only pay for what you need, when you need it. This is why MSPs across the world initiate assessments on all new customer opportunities, as if your customers’ expectations regarding growth didn’t in fact fulfill the expectations, then they’re likely overprovisioned on their on-premises server(s), which is what the Azure Migrate assessment will discover, and rectify with Azure recommendations and server outputs.’
Windows Server Migration
The Azure Migrate: Discovery and assessment tool discovers and assesses on-premises VMware VMs, Hyper-V VMs, and physical servers for migration to Azure; all by creating a Migrate project in the Azure Portal which is a zero-cost workload.
Azure Migrate is also capable of migrating applications, and VDI.
Here’s what the tool does:
i. Azure readiness: Assesses whether on-premises servers, SQL Servers and web apps are ready for migration to Azure.
ii. Azure sizing: Estimates the size of Azure VMs/Azure SQL configuration/number of Azure VMware Solution nodes after migration.
iii. Azure cost estimation: Estimates costs for running on-premises servers in Azure.
iv. Dependency analysis: Identifies cross-server dependencies and optimisation strategies for moving interdependent servers to Azure. Learn more about Discovery and assessment with dependency analysis.
Discovery and assessment use a lightweight Azure Migrate appliance that you deploy on-premises.
- The appliance runs on a VM or physical server. You can install it easily using a downloaded template.
- The appliance discovers on-premises servers. It also continually sends server metadata and performance data to Azure Migrate.
- Appliance discovery is agentless. Nothing is installed on discovered servers.
- After appliance discovery, you can gather discovered servers into groups and run assessments for each group.
SQL Server Migration
Azure Database Migration Service
SQL Server assessments work in an almost identical way to what we’ve just discussed around Win Server assessments but utilising the Azure Database Migration Service. The Azure Database Migration Service is a service that allows you to plan and implement your organisation’s move onto the various Azure SQL platforms, including MySQL alongside other database protocols such as MongoDB and Oracle, from on-premises. It allows for the full transfer of database objects, processes, members, and data from your company’s physical SQL server onto the Azure cloud; and again, like Azure Migrate, it’s a zero-cost product.
Here’s how it works:
There are multiple migration scenarios to consider when utilising the Database Migration Service, as is the multi-faceted nature of Azure SQL, so we’re going to take a brief look at the most common example – migrating an on-premises SQL instance to Azure SQL database.
There are 6 major steps that cover off the planning, implementation, and monitoring of an on-premises to Azure SQL migration:
- Assess and evaluate the on-premises database for any pre-migration compatibility issues
- Migrate the database sample ‘schema’ (the underlying structure of the SQL database)
- Create an instance of Azure Database Migration Service
- Create a migration project within the Azure Database Migration Service
- Implement the migration
- Monitor the migration
Throughout the process, you’ll be utilising a tool called the Data Migration Assistant (DMA), that helps to iron out any compatibility issues on the Azure platform using data from your on-premises solution, move data from one platform to another and ensure that your new Azure SQL database operates in much the same way as your on-premises solution did.