What NOT to do in your server room

Leave unused cables in-place. Do not use cable management. Label no cables.

Use cables of inappropriate length (this is a SCSI cable!):

Plug your most critical servers and SAN into a small stand-alone UPS instead of the large, redundant, UPS battery backup:

Keep old and dead equipment in the rack:

Use the aisle in front of your server racks for old PC storage:

Run cables through unusual pathways that require un-racking servers to move a cable:

Stack equipment back-to-back and resting on top of each other: