Hi there @Larsus123,
Just to be sure. You are talking about log in “…\knime-workspace\.metadata\knime”?
What are your log file level preferences? If set to WARN then modifying/running workflow which produces no errors or warnings will not update log file obviously. Also if set at INFO you will see no DEBUG data.
You can’t have only log data from that run. You will have previous log data as well.
You can increase log file size. Check here. This link also talks a bit more about logging so feel free to explore it.
Additionally you can enable per workflow logs. This preference together with above mentioned log file level are defined in File → Preferences → KNIME.
Hope this helps.
Br,
Ivan