Best answer by Zdenek Pala
Logging is controlled on the Admin page under Diagnostics->advanced->system->web terminal.
There are three controls on the diagnostics->web terminal page. There is a number field that sets the max number of logs. The default is 10,000.
A check box "Enable Logging" toggles whether or not the system will log the web terminal sessions. Web terminal session logs are created in the system log directory under web_terminal_sessions//_.
There is a button that when clicked will remove all log files.