Hi Martin,
Just increase the LOGSECOND parameter to a decent value say 100, as you have enough space in log directory.
This parameter will allocate log file as when require. and once committed will free it up.
$ db2 connect to <DBSID>
$ db2 update db cfg using logsecond 80 immediate
This is a dynamic and will not required a restart.
Regards,
Prithviraj.