Power strategy for first server rack

Horizontal PDUs are a mess -- In my experience there's nothing that can be done to make these neat: You can bundle your cables neatly down the side of your rack, but when you get to the PDU they fan out into a rat's nest.

For vertical ("Zero-U") PDUs you can acquire custom-length power cables (they're available from various suppliers, usually in the same assortment of lengths you can get ethernet cables in - 1' 3' 5' 7' 14' etc.). The cables can then be bundled and tucked into the side of the rack the same way you would with ethernet cables - I use velcro ties to hold mine to the side of the rack so they don't trap server exhaust...

Some other tips:

• Bundle your cables either by branch (if you have A/B power) or by machine.
  (If you have A/B power you can also use different color power cords to distinguish them - e.g. Black/White)
• Label your cables (Either on the plug or on the PDU) so you know what you're unplugging
• Remember to leave designated power points for a crash cart (keyboard/monitor) if necessary.
  (If you do not have an in-rack keyboard/mouse it IS necessary - a KVM or IP-KVM is not always an adequate substitute)
• Don't run your AC power cables on the same side of the rack as your ethernet cables
  (You already seem to be aware of this)

Multiple PSUs in servers are ok but not a magic bullet. Often when things to do with power go they take out other things around them eg. the backplane that your redundant psus both connect to. Far more likely to keep running if you have two servers on seperate UPSs.

Best of all is to work in redundancy at your application or platform layer so that machines or racks can go out without it causing a problem but when you haven't got the budget for that you can still reduce the risk by having spares of any non redundant equipment ready to swap out, but also by keeping things simple. A fancy managed PDU is far more likely to go down than a dumb power bar.

Also it is worth bearing in mind that many small businesses simply can't do things the proper way or choose to do things the cheapest way and live with the consequences if they happen. I've seen inexperienced admins go out of their way to avoid doing things a certain way that have been slated around here or similar sites only to put something worse in place. A less than ideal solution is often better than nothing.