# File System Corruption and Application Rollback Question

**URL:** <https://forum.legato.io/t/file-system-corruption-and-application-rollback-question/5563>\
**Category:** Uncategorized\
**Created:** [January 7, 2021, 3:24pm UTC](https://forum.legato.io/t/file-system-corruption-and-application-rollback-question/5563 "2021-01-07T15:24:25Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![piinst](https://avatars.discourse-cdn.com/v4/letter/p/919ad9/32.png) [@piinst](https://forum.legato.io/u/piinst)\
**Post date:** [January 7, 2021, 3:24pm UTC](https://forum.legato.io/t/file-system-corruption-and-application-rollback-question/5563/1 "2021-01-07T15:24:26Z")

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Suppose due to a hardware error in the flash file system the code for a Legato application installed using the update command is corrupted. Would the following happen when an attempt is made to start the application:

- a checksum error on the application code is detected.
- the application is rolled back to the previously installed version.

The documentation I’ve seen suggests this but is not entirely clear. Also there seems to be some role for a configuration tree, it appears to be created automatically, does the application have to do anything explicitly?

Thanks for any advice.

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**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.legato.io/jyijyi/32/822_2.png) [@jyijyi](https://forum.legato.io/u/jyijyi)\
**Post date:** [January 7, 2021, 4:13pm UTC](https://forum.legato.io/t/file-system-corruption-and-application-rollback-question/5563/2 "2021-01-07T16:13:40Z")

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here says:

`If the overlay version of the runtime environment ever gets corrupted, the factory install version of Legato will replace the faulty version. If a new version of Legato is installed through the `` .cwe install process, that new version of Legato will then replace and become the new base version.`

> **[Updates - Legato Docs](https://docs.legato.io/latest/conceptsUpdates.html)**
>
> legato™ is an open source Linux-based embedded platform designed to simplify connected IoT application development

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**Author:** ![piinst](https://avatars.discourse-cdn.com/v4/letter/p/919ad9/32.png) [@piinst](https://forum.legato.io/u/piinst)\
**Post date:** [January 7, 2021, 5:58pm UTC](https://forum.legato.io/t/file-system-corruption-and-application-rollback-question/5563/3 "2021-01-07T17:58:09Z")

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Thanks for the reference. So everything under /legato will get restored including applications?

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**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.legato.io/jyijyi/32/822_2.png) [@jyijyi](https://forum.legato.io/u/jyijyi)\
**Post date:** [January 8, 2021, 12:48am UTC](https://forum.legato.io/t/file-system-corruption-and-application-rollback-question/5563/4 "2021-01-08T00:48:15Z")

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I think so

`the factory install version of Legato will replace the faulty version.`

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**Author:** ![piinst](https://avatars.discourse-cdn.com/v4/letter/p/919ad9/32.png) [@piinst](https://forum.legato.io/u/piinst)\
**Post date:** [January 8, 2021, 9:33pm UTC](https://forum.legato.io/t/file-system-corruption-and-application-rollback-question/5563/5 "2021-01-08T21:33:17Z")

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Thanks for the help.