hotplugged

Hotplugged refers to a device or component that has been connected to a running system using hot-plug capabilities. Hot-plugging allows hardware to be added or removed without powering down the computer, in contrast to cold plugging where a system must be shut off first.

Common hot-plug capable interfaces include USB, PCI Express, and SATA hot-swap drive bays. Many servers, professional workstations, and consumer devices rely on these interfaces to enable dynamic expansion or maintenance. The hardware includes controllers designed to detect new devices and initiate necessary initialization without interrupting the system's operation.

The process of hot-plugging involves both hardware and software components. When a device is connected, the controller signals the operating system, which must support hot-plug events. The OS loads appropriate drivers, assigns resources, and, for storage devices, may mount the volume or present a new peripheral to the user. Dynamic enumeration and safe removal procedures are essential to avoid data loss.

Safe removal is a key consideration for hot-plugged devices. Users are typically required to stop I/O operations or use an OS-specific "safely remove" or eject action before physically disconnecting a device. Removing a device during active I/O can lead to data corruption, incomplete writes, or hardware errors.

Examples of hot-plugged devices include a USB flash drive added to a computer, a PCIe network card inserted into a running server (in hot-plug capable systems), or a hot-swapped SATA drive in a server’s drive bay. While hot-plugging provides flexibility and reduces downtime, not every device or interface supports it, and proper procedures are important to maintain data integrity and system stability.