Validating cluster resource name
Identifying a 3 geographic location can be challenging for some companies, but with the advent of cloud based utility computing like Amazon EC2 and Go Grid, it is well within the reach of all companies to put a file share witness in the clouds and have the resiliency required for effective multi-site clusters.
In fact, you may consider the cloud itself as your secondary data center and just failover to the cloud in the event of a disaster.
I mentioned “cross-subnet failover” as a great new feature of Windows Server 2008 Failover Clustering, and it is a great new feature.
However, SQL Server has not yet embraced this functionality, which means you will still be required to span your subnet across sites in a SQL Server multi-site cluster.
Where should I put the server that is hosting the file share? This is certainly a valid option for disaster recovery, but not so much for high availability.
If the entire site fails (including the Primary node and the file share witness) the Secondary node in the secondary site will not come into service automatically, you will need to force the quorum online manually.
Before we jump right in to the details, let’s take a moment to discuss what exactly a multi-site cluster is and why I would want to implement one.
This is the preferred configuration as it allows for automatic failover in the event of a complete site loss and eliminates any the possibility of a failure of the secondary site causing the primary node to go offline.
By having a 3 site host the file share witness you have eliminated any one site as a single point of failure, so now the cluster will act as you expect and automatic failover in the event of a site loss is possible.
For a detailed description of the quorum types, have a look at this article.
The most common cause of confusion with the Node and File Share Majority quorum is the placement of the File Share Witness.
As of Tech-Ed 2009, the SQL Server team reported that they plan on supporting this feature, but they say it will come sometime after SQL Server 2008 R2 is released.