icecast now has a setting named: /tmp/dump-example1.ogg Is it possible that you in a later version make an admin trigger to enable/disable this feature. So u can specify when it shall start dumping, and when to stop instead of dumping the whole stream.

This is specially handy when u only need to record parts of your stream, like a live show instead of the whole stream which could take up loads of disk space.

regards, ^Naveed^