SunOS machines and many Unixes had an rwalld daemon, which listened for 'remote write all' messages. I (in Australia) had to contact my brother (in Germany) ur

SunOS machines and many Unixes had an rwalld daemon, which listened for 'remote write all' messages. I (in Australia) had to contact my brother (in Germany) urgently one day. So I 'rwall'd the machine that I knew he used most often. To great success.