Yes, you can cancel the validation wizard. It is a read-only diagnostic process, and stopping it will not harm your running services or the cluster database.
The validation is stuck because Cluster Eviction was not performed before you removed the computer from the domain. Even though you removed PWGIRSQL2 from the Active Directory domain, the Cluster Database (ClusDB) running on PWGIRSQL1 still lists PWGIRSQL2 as a configured member node. The validation wizard reads the configuration, sees a 3-node cluster, and is attempting to contact PWGIRSQL2 via RPC/WMI to query its "Cluster Core Groups." Since the machine is off the domain and likely unreachable, the wizard is hitting a long TCP timeout (often 5-10 minutes per check) waiting for a response that will never come.
=> Terminate the Validation Cancel the wizard or kill the process. Do not wait for it.
=> Force Evict the "Ghost" Node You must remove the metadata of PWGIRSQL2 from the cluster so PWGIRSQL1 and PWGIRSQL3 stop trying to communicate with it.
Open Failover Cluster Manager on PWGIRSQL1.
Go to Nodes. PWGIRSQL2 should show as "Down" or "Refused connection."
Right-click PWGIRSQL2 > More Actions > Evict.
If the GUI hangs or fails because it cannot contact the node to "gracefully" evict it, use PowerShell with the Force switch to rip it out of the configuration:
Remove-ClusterNode -Name PWGIRSQL2 -Force
=> Verify Quorum Once evicted, verify that your cluster still has Quorum with the remaining nodes (PWGIRSQL1 and PWGIRSQL3). Since you have an even number of nodes (2) remaining, ensure you have a Witness configured (File Share Witness or Disk Witness) to prevent a split-brain scenario, or ensure your NodeWeight settings are correct.
=> Skip Validation for Now Do not run the validation wizard again immediately. Your priority is operational stability. Validation is resource-intensive and sensitive to the network instability caused by the recent changes. Focus on verifying that your SQL resources are online on PWGIRSQL1 or PWGIRSQL3.
VP