Hot swapping or hot plugging is a term used to describe replacing system components without shutting down the system. Hot swapping describes changing components without interruption to the system, hot plugging describes changing or adding components which interact with the operating system. Both terms describe the ability to remove or replace components of a machine while it is operating. A well-known example of this functionality is Universal Serial Bus (USB). It allows users to add and remove components such as a mouse, keyboard, or printer.

The D-Link DNS-321, DNS-323, and DNS-343 DO NOT support hot swapping or hot plugging. The unit must be powered down before adding or removing any hard drives to the system.