SQL 2017 Always-On AG Pt. 1: Introduction

In this series of posts I will show you how to configure SQL 2017 on Windows Server 2016 with Always-on Availability Groups. I will also be pointing out Nutanix AHV and VMware vSphere configuration best practices along the way. As you will see, 98% of the configuration is hypervisor independent.

SQL Always-on Availability Groups is no longer "new", and is now the preferred HA option for SQL (assuming your applications support it). Gone are the days of shared SCSI disks/LUNs! SQL AAGs were introduced with SQL 2012, and have been enhanced to various degrees with each release. For "full feature" AAGs, you must use the Enterprise edition of SQL. "Basic" availability groups are available in SQL 2016 and 2017 standard edition, but are quite feature limited. You can read about basic AAGs here, directly from Microsoft. This installation series will only cover the enterprise edition of AAGs, as basic AAGs have quite limited features. A few years ago I wrote a similar set of blogs posts for SQL 2014, which you can find here.

Most virtualization or general IT administrators do not have deep DBA skills, so this series is aimed at the general IT administrator and makes general configuration recommendations along the way. Each SQL instance is unique, and will likely deviate from generic settings in this series. So just take the sizings in this series as an example, and adjust accordingly for your needs. CPU, disks, memory and such are all workload and application dependent. Follow your application best practice recommendations, when available.

As previously mentioned, the vast majority of the settings in this guide are hypervisor and storage platform independent. If, however, you are a Nutanix customer I strongly suggest you download our SQL Best Practices Guide, which I was a contributing author. If you are using the VMware platform, I also recommend buying the "Virtualizing SQL Server with VMware." The book has a plethora of advanced SQL advice, which is applicable to any hypervisor. So even if you aren't using vSphere, the book has valuable configuration and performance tuning advice that pairs nicely with Nutanix AHV or Microsoft Hyper-V.

Today virtualizing SQL is no longer considered unusual, and in fact is one of the most popular applications to virtualize. However, that doesn't mean you can just "click next" or use all the defaults and expect tier-1 performance or availability. This series will give you a good starting point for your enterprise SQL 2017 deployments.