# Downgrade from backup **URL:** \ **Category:** Elasticsearch\ **Created:** [October 28, 2016, 10:41am UTC](https://discuss.elastic.co/t/downgrade-from-backup/64272 "2016-10-28T10:41:19Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Attila\_Nagy](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/attila_nagy/32/46906_2.png) [@Attila\_Nagy](https://discuss.elastic.co/u/Attila_Nagy)\ **Post date:** [October 28, 2016, 10:41am UTC](https://discuss.elastic.co/t/downgrade-from-backup/64272/1 "2016-10-28T10:41:19Z")
Hi, With ES5 released, I wonder whether it would be possible to downgrade to ES2.4 somehow, if something fails? The exact question is: is it possible to do these steps? - in-place (or backup/restore) upgrade from ES2.4 to ES5 - use ES5 for some time (not using any of its new features, no new indexes or mappings created) - backup (from ES5) and restore the data to an ES2.4 cluster ---
**Author:** ![ywelsch](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/ywelsch/32/7751_2.png) [@ywelsch](https://discuss.elastic.co/u/ywelsch)\ **Post date:** [October 28, 2016, 10:57am UTC](https://discuss.elastic.co/t/downgrade-from-backup/64272/2 "2016-10-28T10:57:28Z")
No, that's not possible. ES 5.0.0 brings a new major version of Lucene for which the BWC bits are stated as follows (see Section File Formats [here](http://wiki.apache.org/lucene-java/BackwardsCompatibility)): > Older releases are never guaranteed to be able to read indexes generated by newer releases. When this is attempted, a predictable error should be generated. The Lucene segments written or merged by ES 5.0.0 can't be read by Lucene bundled on ES 2.x. ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [July 5, 2017, 10:08pm UTC](https://discuss.elastic.co/t/downgrade-from-backup/64272/3 "2017-07-05T22:08:46Z")