# Questions about upgrading ES 6 -\> 7

**URL:** <https://discuss.elastic.co/t/questions-about-upgrading-es-6-7/250238>\
**Category:** Elasticsearch\
**Created:** [September 28, 2020, 5:00pm UTC](https://discuss.elastic.co/t/questions-about-upgrading-es-6-7/250238 "2020-09-28T17:00:01Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![rdragan](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/rdragan/32/51129_2.png) [@rdragan](https://discuss.elastic.co/u/rdragan)\
**Post date:** [September 28, 2020, 5:00pm UTC](https://discuss.elastic.co/t/questions-about-upgrading-es-6-7/250238/1 "2020-09-28T17:00:02Z")

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Hey,

We are planning to do an online 6-\>7 upgrade for our ES clusters, and we are looking into ways of rolling back safely from 7 to 6 in case something bad happens. The ES docs state that once the upgrade starts, the ES cluster will run into a backwards-compatible mode and will start using ES7 features after all nodes are fully upgraded. To get a better understanding of this, I have a few questions:

1. Is this switch happening automatically? Would it be possible to prevent it? (via a code change, or a setting change)
2. What would be the place in the code where this switch would happen?

Thank you,  
Relu

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**Author:** ![Christian\_Dahlqvist](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/christian_dahlqvist/32/4617_2.png) [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)\
**Post date:** [September 28, 2020, 5:53pm UTC](https://discuss.elastic.co/t/questions-about-upgrading-es-6-7/250238/2 "2020-09-28T17:53:51Z")

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If you need to be able to roll back to version 6 you will need to create a snapshot before you start the migration so you can revert to this. Once indices have been touched by version 7, they will no longer be readable from version 6 as Elasticsearch does not support downgrades.

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**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [October 26, 2020, 5:53pm UTC](https://discuss.elastic.co/t/questions-about-upgrading-es-6-7/250238/3 "2020-10-26T17:53:57Z")

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