All of our production servers have pairs of redundant cables plugged into the back: a pair of power cords, a pair of ethernet cables, often a pair of fiber cables. This presents a problem when you need to pull a server out of the rack at 10pm on a Saturday night to replace a bad stick of RAM - How do you absolutely guarantee that each cable gets plugged back into the correct port?

Yes, most of the time the cables are labeled properly, but it pays to be a bit cautious, and that’s when I reach into my bag and pull out some twist ties.

Specifically, I will tie a Red twist tie around the Right cable in each pair. It’s quick, the twist ties are cheap and reusable, and it’s a good line of defense against the #1 cause of production outages: human error.