hot swap

The ability to remove a failed member of a redundant disk array and replace it with a good drive without bringing down the server or interrupting transactions that involve other devices.

To add, remove, or replace a disk in a NetApp appliance while the appliance is running.

In an electronic device, of a subassembly or component therein (e.g. circuit card), the act or process of removing and replacing the subassembly or component without first powering down the device. Note: Hot swapping of components in devices or environments not designed to support such practice may result in damage to the component or device, or may pose a spark hazard even if the primary power has been removed. And, in some computing devices, hot swapping may not be appropriate because new components may be recognized only during boot-up.