# System Fault Tolerance

> Mediated Wiki article. Canonical URL: https://mediated.wiki/source/System_Fault_Tolerance
> Markdown URL: https://mediated.wiki/source/System_Fault_Tolerance.md
> Source: https://en.wikipedia.org/wiki/System_Fault_Tolerance
> Source revision: 1329191637
> License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/)

- (DELETE) This text describes "product name", is not an encyclopedic entry.

In [computing](/source/Computing), **System Fault Tolerance** (**SFT**) is a [fault tolerant system](/source/Fault_tolerant_system) built into [NetWare](/source/NetWare) [operating systems](/source/Operating_system). Three levels of fault tolerance exist:

- SFT I 'Hot Fix' maps out bad disk blocks on the file system level to help ensure data integrity (fault tolerance on the disk-block level)

- SFT II provides a [disk mirroring](/source/Disk_mirroring) or duplexing system based on [RAID](/source/RAID) 1; mirroring refers to two disk drives holding the same data, duplexing uses two data channels/controllers to connect the disks (fault tolerance on the disk level and optionally on the data-channel level).

- SFT III is a server [duplexing](/source/Redundancy_(engineering)) scheme where if a [server](/source/Server_(computing)) fails, a constantly synchronized server seamlessly takes its place (fault tolerance on the system level).

## References

- [Novell NetWare 4.2 documentation](http://www.novell.com/documentation/nw42/index.html?cncptenu/data/hdqefjoy.html)

This computer science article is a stub. You can help Wikipedia by adding missing information.

- [v](https://en.wikipedia.org/wiki/Template:Comp-sci-stub)
- [t](/source/Template_talk%3AComp-sci-stub)
- [e](https://en.wikipedia.org/wiki/Special:EditPage/Template:Comp-sci-stub)

---
Adapted from the Wikipedia article [System Fault Tolerance](https://en.wikipedia.org/wiki/System_Fault_Tolerance) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/System_Fault_Tolerance?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.