As a SQL Server professional, it is important to have a good understanding of the tools and techniques available to troubleshoot and diagnose issues related to SQL Server clusters. One such tool that can be extremely helpful in this regard is the cluster log.

When working with SQL clusters, it is not uncommon to encounter situations where a SQL resource fails to come online. In such cases, the cluster log can provide valuable insights into the underlying issues. While the event log does contain some information related to failover clustering, it is often not detailed enough. This is where the cluster log comes in.

In Windows Server 2003, the cluster log was automatically generated. However, starting from Windows Server 2008, the log needs to be manually generated using the cluster.exe command. This change was a good decision by Microsoft, as it allows for more control over when the log is generated.

To generate the cluster log, open a Command Prompt with Administrator rights and type the command “cluster log /g”. This will generate a file named cluster.log, which will be stored in the %windir%\Cluster\Reports directory on each node of the cluster.

If you are using a later version of Windows Server where cluster.exe is not available, you can use the PowerShell method to generate the cluster log. The command to use is “Get-ClusterLog”. However, if you encounter an error stating that the command is not recognized, you will need to import the failover cluster module using the “Import-Module FailoverClusters” command.

Once the cluster log is generated, you can review it to identify any glaring error messages or issues that may be preventing the SQL resource from coming online. The log can provide valuable information about the state of the cluster and help in troubleshooting and resolving the issue.

It is worth mentioning that the cluster log can be customized based on your specific needs. However, in most cases, the default parameters should be sufficient.

Have you ever encountered a situation where the cluster log helped you in troubleshooting a SQL cluster issue? Sharing your experiences and insights can be of great help to others facing similar challenges. So, if you have used the cluster log or any other techniques to diagnose SQL cluster issues, we would love to hear from you.

Learning from each other is a great way to expand our knowledge and improve our skills as SQL Server professionals. So, let’s continue to share and learn together!