One can also adjust /etc/matrix-synapse/log.yaml, but I agree some change should be made to debian/log.yaml (default configuration file) to reduce the maximum size of logs stored and/or log level to WARN (WARNING).
I also agree the logs should be compressed on daily rotation, but it remains unclear to me how one would change this in Synapse without big hacky behaviors. Preferably I'd use logrotate(8) if at all possible. This might be helpful: https://docs.python.org/3/library/logging.handlers.html So maybe change logging.handlers.RotatingFileHandler in debian/log.yaml to WatchFileHandler (use with logrotate(8)) if I've understood correctly. TimedRotatingFileHandler is an alternative to let Python manage log rotation by itself, but no logs will be compressed then.
