I have launched three EC2 Windows_Server-2019_SQL_2019_Standard instances. How can I implement Always On Failover Cluster Instances (FCI) on these existing SQL Servers. I can only find details like when you install SQL first time that time only you can choose the Failover Clustering option.

Note: I have already created WSFC Cluster using these three nodes.


2 Answers 2


You cannot convert an existing standalone instance to an Failover Clustered Instance (FCI).

You can configure standalone instances to be part of an Availability Group, but FCIs use a separate install path, and must be configured from the point of install.

From the AWS docs

FCIs require some form of shared storage—disks on a storage area network (SAN), file shares on Server Message Blocks (SMBs), or locally attached storage with Storage Spaces Direct (S2D), SIOS Datakeeper, or Amazon FSx.

Amazon provides a very though overview and deployment guide for installing SQL Server FCIs using Amazon FSx. It is a comparatively complex configuration, compared to building standalone instances, or even Availability Groups.

Note that Amazon's recommendations in the deployment guide do not use AMIs with SQL Server already installed, but depend on your purchasing licensing on your own:

This Quick Start deploys MSSQL in Bring-Your-Own-License mode. It does not support deployment of MSSQL license-included Amazon Machine Images (AMIs).


I can launch SQL Server FCI over the existing EC2 Windows Server with SQL. I have two node cluster (This is a limitation of Microsoft for Standard Edition). The SQL Installation file is present in the C: drive of the Windows Machine. You can use this installation file and launch more SQL Server Instances.

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