Hot swapping, or "hot plug and unplug", refers to the ability to plug and unplug hardware while the computer is in operation. With appropriate software, you can plug in and unplug peripherals that support hot-swapping without having to power down the device, which can cause the host computer or peripherals to burn out, and enables real-time detection and use of new devices. Compared to Plug-and-Play, the hardware and software requirements for Hot Swap also include the order in which the power, signal, and ground wires are contacted.
Second, the characteristics
Hot plug first appeared in the field of servers, in order to improve the ease of use of the server and proposed. USB hot plug in our usual computer usually have a USB interface, this interface will be able to realize the hot plug. If there is no hot-plugging function, even if the disk damage will not cause data loss, the user still needs to temporarily shut down the system, so that the hard disk can be replaced. With hot-plug technology, you can simply flip a switch or turn a handle to remove the hard drive, and the system will still function without interruption.
3. How it works
Features
Since the 586 era, system buses have been expanded with an external bus, so our concerns in this area can be eliminated.
Motherboard BIOS
Since 1997, the new BIOS has added support for Plug and Play functionality. Although this Plug and Play support does not mean full hot-swap support, but only hot-add and hot-replace support, this is the most popular technology we use for hot-swapping, so this problem with the motherboard BIOS can also be overcome.
Operating systems
In terms of operating systems, Windows 95 began to support plug-and-play, but support for hot-plugging is very limited until NT 4.0 began, Microsoft began to notice that the NT operating system will be aimed at the server field, and this field of hot-plugging is a very critical technology, so the operating system has increased the number of full hot-plugging This feature has been carried over to the NT-based Windows 2000/XP operating systems, so as long as you use an operating system that is NT 4.0 or higher, the operating system provides complete support for hot-plugging.
Device drivers
Drivers for Windows NT, Novell's Netware, and SCO UNIX all integrate hot-plugging functionality, so as long as you choose a driver for one of the above operating systems, the last element of hot-plugging will be in place.
In general, a complete hot-plugging system consists of hot-plugging system hardware, hot-plugging software and operating systems, hot-plugging device drivers, and hot-plugging user interfaces.
Four, hot-plugging benefits
The benefits of adding hot-plugging to the system include:
1, in the case of the system power on the damaged module removed, but also in the case of power on to do the update or expansion without affecting the system operation.
2, because of the increased reliability of hot-plugging parts, they can also be used as a disconnect, and because hot-plugging can be automatically recovered, there are many hot-plugging chip for the system to provide a signal of the power supply situation of the line, so that the system to do fault analysis, therefore reducing costs.