Setup New Windows Clustering on AlwaysOn Database Servers

1. Make sure to install “Windows Failover Cluster” feature on all nodes in the cluster.
2. Open up “Failover Cluster Manager”.
3. Right click on Failover Cluster Manager and select “Create Cluster”.
4. Select list of servers to be in the cluster.
5. Run Cluster Validation.
6. Provide a “Cluster Name”.
7. Provide a “Networks/IP Address”.
8. Setup a listener is optional but recommended for automatically failover.

Note:

The login account setting up the clustering needs to be a “domain admin” or you will get the following error…

Create computer object xxxxx on domain controller xxxxx in organizational unit xxxxx. Access is denied. 

Crete the Windows Failover Cluster first, then configure the Availability Group in SSMS. Once the AG is created in SSMS, a role will be auto setup in Windows Failover Cluster.

Sources:

Configure failover clusters, storage controllers and quorum configurations for SQL Server Always On Availability Groups