Recently I built a test environment and was in need to investigate a few issues in the ULS Logs. However, to my dismay, I found that there was no information in them. They were being created, but all had a 0 KB size. As one would first attempt, I restarted the SharePoint 2010 Tracing service, and found no resolve.
As I looked at the service in compared to another working SharePoint 2010 farm, I found the service was running as ‘Local System’ on the working farm, and in my test environment it was running as one of the SharePoint service accounts.
I changed the ‘Log on as’ to ‘Local System’ for the SharePoint 2010 Tracing service, then restarted the service, and all was back in order and ULS logs were capturing data.