On Premise Power BI Server - Logs & Debugging

Hi,

I had an issue today where vmware admin reduced the spec on our PowerBi server.

They used an average consumption figure and decided to drop the memory allocated and cores.
Reports ground to a halt, the 'loading wheel' span, managers got annoyed etc and the quick fix was to  return the box to spec.

However, my background is the sql server not powerbi , and this raised the following questions - 

Which of the log files should I examine to see what was happening at this time?

Is there a method or tool I can import these files with?

Any sugestions welcome, searching is leading me round in circles as most powerbi results seem to be about the cloud service.

Thank you

Rich