Hot-swap means replacing a component while the server is running. Cold-swap requires powering down. Knowing which is which prevents downtime and data loss.
Hot-Swap Components
- Hard drives / SSDs — All enterprise servers (SAS, SATA, NVMe in hot-swap bays)
- Power supplies — Redundant PSUs hot-swap by design
- Fans — Most 2U+ servers support hot-swap fans
- SFP transceivers — Hot-pluggable by specification
Cold-Swap Components (Power Down Required)
- CPU — Always cold-swap
- Memory (DIMMs) — Always cold-swap
- RAID controller — Always cold-swap
- NIC cards — Always cold-swap (PCIe slot)
- GPU — Always cold-swap