UNIX and Linux System Administration Handbook, 5th Edition

28	Monitoring

A commitment to monitoring is the distinguishing characteristic of a professional system administrator. Inexperienced sysadmins often leave systems unmonitored and allow failures to be “detected” when a frustrated, angry user calls the help desk because they’re unable to complete an intended task. Slightly more clued-in administrative groups set up a monitoring platform but disable after-hours notifications because they are too bothersome. In either case, fire fighting and hilarity ensue. These approaches adversely affect the enterprise, complicate recovery efforts, and give the sysadmin team a bad reputation. ...