until now i have only fess_config.properties and contentlength.xml persistent.
I discovered that with every fess container recreatrion (15.5.1) the value “fess_config.properties” in General Config changes back to 5 in the fess ui.
How to make this permanent? In which file is this value saved?
The /opt/fess path is controlled by the FESS_OVERRIDE_CONF_PATH environment variable. If you place system.properties under that path, it will be prioritized over the default configuration. So in a container setup, mounting a directory to FESS_OVERRIDE_CONF_PATH and placing system.properties there will make the configuration persistent across recreations.