Hot Spare

What Does Hot Spare Mean?

A hot spare is a backup device that is usually in standby mode but becomes immediately available if a primary computer component fails, malfunctions or goes offline. It is an operative component and considered part of the working system. Hot spares can be power supplies, A/V switches, hard disk drives or network printers. The device is considered hot because it is turned on, although it is not continually active in the system.


A hot spare may be used for both hardware and software backup.

Techopedia Explains Hot Spare

A hot spare is a failover component that offers reliability in system configurations. A failover occurs without user involvement and is generally automatic when system failure is detected. It acts like a secondary system that can be switched on if the primary system fails and is designed to rebuild automatically with little or no interruption.

A hot spare is typically a solitary, critical device that a computer needs in order to function. When there is a problem, the system is altered to incorporate the hot spare with its structure. It is intended as a temporary fix and designed to substantially increase system availability during the exchange process.

A hot spare also decreases the mean time of recovery for a device and prevents potential data loss due to disk failure. However, a hot spare does not provide 100 percent protection against momentary system loss when switching to the backup.


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Margaret Rouse
Technology Expert

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.