hot swap
also: hot-swap, hotswap, hot-plugging
Hot swap is the ability to remove and replace hardware components while the system is running without shutting down or interrupting service.
Hot swapping allows you to physically insert or remove hardware—such as hard drives, RAM, USB devices, or network cards—from a live system without powering down. The operating system and applications continue running uninterrupted, and the new hardware is detected and initialized automatically.
Common examples include replacing a failed disk in a RAID array, adding or removing USB devices, or connecting a new network interface. This is particularly valuable in server environments where downtime is costly.
Not all hardware supports hot swapping; it requires both the device and the system to be designed for it. For instance, most modern SATA drives support hot swap in external enclosures or hot-swap bays, and USB devices are inherently hot-swappable. Legacy IDE drives do not support hot swap.