>Also: never make more than one state change at a time. Yes, good point, and a fundamental tenet of troubleshooting in general. Also to make each change revers

>Also: never make more than one state change at a time. Yes, good point, and a fundamental tenet of troubleshooting in general. Also to make each change reversible, as far as possible. You can bork a system by one innocent / ignorant change to a config file in /etc, for example. A lot of us learned it on our own (sometimes the hard way, ha ha, got a few stories there), later I also saw it mentioned in an early part of the O'Reilly book Unix System Administration by Aileen Frisch. Very good book, as is another book (thick one) by Nemeth et al - the Unix System Administration Handbook (later there was a Linux edition too).