Swap techniques are divided into auto-swap, hot-swap, warm-swap and cold-swap. Faulty system components such as circuit boards, hard disks, controllers, data cables, etc. are always exchanged for replacement units in the event of a fault. Depending on the swap technology, the exchange takes place during operation, after the programs have been shut down or in a switched-off state.
Auto-swaps occur immediately without physically replacing a system component or human intervention. The spare units( RU) for hot swap are integrated into the system as redundant units, known as hot spare units, and automatically take over the functions of the faulty system component in the event of a fault.