Fault Tolerance

What Does Fault Tolerance Mean?

Fault tolerance is the way in which an operating system (OS) responds to a hardware or software failure. The term essentially refers to a system’s ability to allow for failures or malfunctions, and this ability may be provided by software, hardware or a combination of both. To handle faults gracefully, some computer systems have two or more duplicate systems.

Techopedia Explains Fault Tolerance

Fault tolerance software may be part of the OS interface, allowing the programmer to check critical data at specific points during a transaction.

Fault tolerance can include:

Responding to a power failure (the lowest level of fault tolerance)
Immediately using a backup system in the event of a system failure
Allowing mirrored disks to immediately take over for a failed disk
Multiple processors working together and comparing data and output for errors, then immediately correcting the detected errors.

In general, 100% fault tolerance can never be achieved due to cost constraints.

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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.

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