# About CCR
**URL:** https://discuss.elastic.co/t/about-ccr/162311
**Category:** Elasticsearch
**Created:** [December 28, 2018, 7:48am UTC](https://discuss.elastic.co/t/about-ccr/162311 "2018-12-28T07:48:42Z")
**Posts on this page:** 9
**Page:** 1
### Author:  [@zhutong](https://discuss.elastic.co/u/zhutong)
#### Post date: [December 28, 2018, 7:48am UTC](https://discuss.elastic.co/t/about-ccr/162311/1 "2018-12-28T07:48:42Z")
I am currently upgrading cluster from 6.2.2 to 6.5.4 and mainly want to use Cross Cluster Replication, but how do I support Cross Cluster Replication with my old index in 6.2.2.
---
### Author:  [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)
#### Post date: [December 28, 2018, 8:28am UTC](https://discuss.elastic.co/t/about-ccr/162311/2 "2018-12-28T08:28:49Z")
CCR requires all clusters and nodes to be version 6.5 or above.
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### Author:  [@zhutong](https://discuss.elastic.co/u/zhutong)
#### Post date: [December 28, 2018, 8:33am UTC](https://discuss.elastic.co/t/about-ccr/162311/3 "2018-12-28T08:33:18Z")
Thanks for your answer, because the amount of index data in 6.2.2 is too large, rebuilding the index will take great risks. Is there any way to support CCR for the old index?
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### Author:  [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)
#### Post date: [December 28, 2018, 8:51am UTC](https://discuss.elastic.co/t/about-ccr/162311/4 "2018-12-28T08:51:18Z")
Have you tried replicating this index? Is it now hosted on 6.5 nodes?
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### Author:  [@zhutong](https://discuss.elastic.co/u/zhutong)
#### Post date: [December 28, 2018, 8:59am UTC](https://discuss.elastic.co/t/about-ccr/162311/5 "2018-12-28T08:59:05Z")
I tried just now. The cluster is now upgraded to 6.5.4, but the old index cannot be modified to enable soft delete. An exception was thrown when I copied the index to the follower cluster.
{
"error" : {
"root\_cause" : [
{
"type" : "illegal\_argument\_exception",
"reason" : "leader index [test\_index01] does not have soft deletes enabled"
}
],
"type" : "illegal\_argument\_exception",
"reason" : "leader index [test\_index01] does not have soft deletes enabled"
},
"status" : 400
}
---
### Author:  [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)
#### Post date: [December 28, 2018, 10:21am UTC](https://discuss.elastic.co/t/about-ccr/162311/6 "2018-12-28T10:21:13Z")
Then you probably need to reindex it, but let’s see if someone else may have some other suggestions.
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### Author:  [@xeraa](https://discuss.elastic.co/u/xeraa)
#### Post date: [December 30, 2018, 12:56am UTC](https://discuss.elastic.co/t/about-ccr/162311/7 "2018-12-30T00:56:26Z")
Yes, the [docs have their own info box for that](https://www.elastic.co/guide/en/elastic-stack-overview/6.5/ccr-requirements.html):
> This means that cross-cluster replication can not be used on existing indices. If you have existing data that you want to replicate from another cluster, you must [reindex](https://www.elastic.co/guide/en/elasticsearch/reference/6.5/docs-reindex.html)your data into a new index with soft deletes enabled.
BTW soft deletes will be enabled by default in 7.0, so any index created there can be used with CCR at any time. For indices on 6.x you must enable soft deletes when creating the index unfortunately.
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### Author:  [@zhutong](https://discuss.elastic.co/u/zhutong)
#### Post date: [January 4, 2019, 7:19am UTC](https://discuss.elastic.co/t/about-ccr/162311/8 "2019-01-04T07:19:42Z")
Many thanks!
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### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [February 1, 2019, 7:19am UTC](https://discuss.elastic.co/t/about-ccr/162311/9 "2019-02-01T07:19:46Z")
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