The benefits of deploying SQL Server using IaaS

Besides IaaS, there is another deployment method for SQL Server: platform-as-a-service (PaaS). Azure SQL Database, or Azure SQL Managed Instance, is PaaS. With PaaS, there is no operating system (OS) or SQL Server instance you need to manage, which includes things such as patching. All of that is done for you. Where that does not work for some is that you may need control over the OS and/or SQL Server choices (version or edition) due to standards, licensing, or other requirements. PaaS provides a more packaged solution that fits the needs of many without needing a dedicated OS and SQL Server instance.

Since IaaS is just a VM with an OS, you can deploy whatever supported combination of OS and SQL Server you desire. One principal difference between IaaS and PaaS is that any automatic administration you would want done by Microsoft is opt-in, whereas PaaS is done for you and you have limited configuration choices. One important reason why many choose IaaS is the ability to make choices you could not otherwise make with something like Azure SQL Database.

That choice extends to being able to use other Azure services, such as Azure Backup1, Azure Security Center2, Advanced Data Security for SQL on Azure VM3, including vulnerability assessment and Advanced Threat Protection, Azure Site Recovery4, and the SQL Server on Azure Virtual Machines resource provider (covered in a later section). This means that you can take advantage of the best of what Azure has to offer for IaaS-based SQL Server deployments.

IaaS facilitates installations of SQL Server in cloud-first environments, "lift and shift" scenarios where you have a requirement to deploy the same version/architecture as on-premises but are migrating to Azure, and, more importantly, hybrid scenarios where IaaS VMs become an extension of on-premises.

For example, you may still be primarily on-premises for most SQL Server installations right now. However, you want to start moving toward using Azure and also have a need for more robust disaster recovery. If you currently use Always On availability groups, one or more IaaS-based replicas could be added to Azure (along with any other required infrastructure, such as Active Directory Domain Services) to extend the existing architecture up to the cloud. Refer to this Microsoft documentation5 to read more about the new high availability and disaster recovery benefits for SQL Server.

All standard SQL Server deployment scenarios apply in IaaS as they do on-premises if you are implementing physical servers or VMs. Most considerations for deploying SQL Server properly on-premises are the same, with slight variations due to Azure, some of which are documented in this chapter and others throughout this book. The rest of this chapter will focus on how to choose a VM and approach things such as sizing.

There is one other benefit associated with choosing Azure for your IaaS SQL Server platform: Microsoft will continue to provide Windows Server 2008 and 2008 R2 as well as SQL Server 2008 and 2008 R2 extended security updates if you still require those versions and need to migrate those workloads to VMs in Azure.