I have a Windows Server 2008 R2 failover cluster with four nodes and four resource groups (each running one SQL Server 2008 R2 instance). The cluster disks are iSCSI LUNs from a Dell EqualLogic storage subsystem. We had some sort of iSCSI issue that caused LUN access problems, and Windows failed over resource groups to different nodes. Then we had a power fluctuation that may have caused a loss of network connectivity between the cluster nodes (not sure, still investigating).
We observed that all of Resource Group 3's resources (network name, disks, SQL Server services, etc) had spontaneously moved over to Resource Group 4, which still contained its original resources.
We are going to attempt to manually move each resource back to Resource Group 3 during a maintenance window.
Any idea what would cause this sort of behavior?
