Simple Unixy mistakes that will ruin your day

[KC9UDX]

Since it's expected that most everyone here is using a Unix or Linux, and there seem to be a lot of users new to the idiom here, I thought it would be nice to have a thread of pitfalls to be aware of.  Experienced users have all been down this road many times.  If you have one or more to contribute, please do.

I'll start with one I ran into recently.  It caused a several-day headache.  Firefox was randomly crashing, and the only thing that would remedy it was to kill ypbind, a rather odd situation.  This was caused by a simple oversight on my part.  In /etc/nsswitch.conf I had the line

Code:

hosts:        files nis dns

where I should have had

Code:

hosts:        files dns nis

I've written a pretty extensive web server, but I've never written a web browser, and can only guess why this is relevant.  So I won't propose a possible explanation.