When you create an AlwaysOn availability group by using the New Availability Group Wizard in Microsoft SQL Server 2012, or when you are performing failover of the AlwaysON Availability Group (AG) every time you may receive a warning message as shows below
The current WSFC cluster quorum vote configuration is not recommended for this availability group.
The above error occurs due to various reasons. and one of which is missing windows OS patch KB 2494036 on all cluster nodes part of the AlwaysON Availability Groups. Verify and apply the mentioned patch and reboot the nodes and the issue should be resolved. However if the issue still persists even after this patch is applied on all the cluster nodes then apply latest Service Pack or Cumulative Update available for SQL Server 2012 or SQL Server 2014.
Starting with Windows Server 2008, failover clustering introduced node based voting where Windows Server Failover Clustering (WSFC) uses a majority of votes to establish a quorum for determining cluster membership. Votes are assigned to nodes in the cluster or to a witness that is either a disk or a file share witness. We can use the Configure Cluster Quorum Wizard to configure the clusters quorum model. When you configure a Node Majority, Node and Disk Majority, or Node and File Share Majority quorum model, all nodes in the cluster are each assigned one vote. However there are limitations to the votes for AlwaysON Availability Groups which involve SQL Server Clustered instance. If a primary or a secondary replica is hosted by a Windows cluster then this replica is configured for an automatic failover without a vote. If this is by design then you may ignore the warning as it still allows the initial setup of AlwaysON Availability Groups and subsequent manual failover of AlwaysON Availability Groups, but the warning will appear each time you try to perform a manual failover.
Also it is possible to configure the votes for each node and customized as per the business requirement. This functionality helps with multi-site clusters where you may want one site to have more number of votes than other sites in a disaster recovery data center. By default all nodes in the cluster have one vote but administrators can change the vote functionality in the quorum model by configuring a particular node to have 0 votes.
This is applicable on below versions of SQL Server
SQL Server 2005
SQL Server 2008 R2
SQL Server 2012
SQL Server 2014
Hope this was helpful.
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