Set Cluster Log Size and Verbosity in Microsoft Server 2008 R2

Recently a critical cluster system had a bit of a hiccup wherein the SQL resource failed between nodes a few times and then gave up. Most of my clusters run on Microsoft Server 2012 R2 so I tend to use PowerShell for everything, in this case the cluster is an older one running Server 2008 R2 and therefore I’m limited in the PowerShell commands available to me.

For a more complete description of these settings and general cluster log understanding see this Microsoft TechNet article – https://blogs.technet.microsoft.com/askcore/2010/04/13/understanding-the-cluster-debug-log-in-2008/

 

PowerShell Method

OK I know I said I wasn’t going to cover PowerShell but let me quickly demonstrate the two commands relevant to this post in case you need them for a newer operating system.

Define Log Size

Define Logging Level

 


 

Right now that we’ve got PowerShell out of the way let’s look at the cluster.exe commands…

 

Confirm Current Cluster Log Settings

First off let’s check the existing cluster properties to see if anyone else has changed them or if they are still on the defaults. I’ve removed all the text expect for the values we need and then shown a screenshot so you get a feel for what the command output looks like.

 

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We can see that the values are currently set to the default – this means 100MB cluster log file size and a verbosity level of 3 (out of 5 levels).

 

Set Cluster Log File Size

Running a command window on one of the cluster nodes –

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Assuming all is well you will receive confirmation from the system that the log file size has been modified.

 

Set Cluster Log Verbosity

Now to set the verbosity level – note that modifying this value can have a performance impact. If we set the value to level 5 that is debug logging which of course means more load. I would strongly suggest you only leverage this level of logging for a short period of time and understand your system sufficiently to know if it can handle this. I’m not saying the logging is going to add a gigantic load to the servers but it’s worth bearing in mind.

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Again, we receive confirmation of the change.

If we now check one last time we should see the cluster properties reflect our changes.

 

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