Hi there.
We have the same issue as mention here:
https://blogs.technet.microsoft.com/isablog/2012/09/18/tmg-logging-to-llq/
The queue has raised by now to 900 GB and if we do the steps mentioned in the article it will fill up the disk where TMG is located.
Is there a way to flush the queue before reestablishing loging?
with best regards
BCR