I ran into an odd problem the other day: I was testing out some configuration changes for a web application by dropping files into /tmp and pointing the application configuration at the appropriate directory. Everything worked out great when testing it by hand…but when starting up the httpd service, the application behaved as if it was unable to find any of the files in /tmp. My first assumption was that had simply missed something obvious like file permissions or that I had a typo in my configuration, but after repeated checks and lots of testing it was obvious that something else was going on.