WSFC Quorum Settings for SQL Always On 3-Node Cluster

Question

Hi. I'm a SQL Server DBA. In my current organization the sys admins build the Windows Server Failover Cluster (WSFC) and DBA team runs the validation report before installing SQL Server Always On 3-node cluster. Our SQL 2014 and 2017 Always On clusters use file share witness for the quorum. The 2019 cluster validation gives warning about the quorum configuration. It is set for the default option which is... "Use default quorum configuration. The cluster determines quorum management options, including the quorum witness.". My question is, is the default cluster managed quorum adequate for 3-node SQL Server 2019 Always On, or should I insist on the file share witness like the 2017 and 2014 clusters. What's the pro/con of the default cluster managed quorum vs file share witness? Thanks.

Answer 1

Hey,

In general 3-node clusters do not require separate disk or file share witness. Might help: https://www.starwindsoftware.com/blog/understand-failover-cluster-quorum

Dynamic Quorum is enabled by default since Windows Server 2012. It will automatically assign votes, in case node fails. In case you want to add additional vote to your cluster or one of the nodes is located in a DR location, I would recommend you to configure file share witness.

In addition, if you want to configure redundant witness, you can use StarWind VSAN to configure disk witness.
https://www.starwindsoftware.com/starwind-virtual-san

Cheers,    
Alex Bykovskyi    
StarWind Software    
Note: Posts are provided “AS IS” without warranty of any kind, either expressed or implied, including but not limited to the implied warranties of merchantability and/or fitness for a particular purpose.

Answer 2

Hello

I'll suggest you to consider Cloud Witness as an option in your Windows Cluster. you won't need the disk resource as quorum