], while corresponding primary shard is still unassigned"
What is the best course of action here? I gather I need to assign the primary shard before I can do anything with the replica. I am concerned given the CorruptIndex exception that the primary shard (and potentially the replica too..) has suffered data losses, so my thinking was that recovering from the replica was my best bet? Is my understanding incorrect here / am I going to have to be content with data losses?
Many thanks
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### Author:  [@warkolm](https://discuss.elastic.co/u/warkolm)
#### Post date: [October 26, 2022, 1:16am UTC](https://discuss.elastic.co/t/unassigned-primary-replica-shard-minimise-data-loss/317393/2 "2022-10-26T01:16:36Z")
What version are you running?
> [@tg295](#):
>
> org.apache.lucene.index.CorruptIndexException: checksum failed (hardware problem?)
That's not good and may indicate data loss. Do you have snapshots?
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### Author:  [@tg295](https://discuss.elastic.co/u/tg295)
#### Post date: [October 26, 2022, 8:31am UTC](https://discuss.elastic.co/t/unassigned-primary-replica-shard-minimise-data-loss/317393/3 "2022-10-26T08:31:32Z")
I'm running 7.13.2. And no I do not have any snapshots...
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### Author:  [@tg295](https://discuss.elastic.co/u/tg295)
#### Post date: [October 28, 2022, 11:05am UTC](https://discuss.elastic.co/t/unassigned-primary-replica-shard-minimise-data-loss/317393/4 "2022-10-28T11:05:15Z")
does anyone have any recommendations for how to proceed?
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### Author:  [@tg295](https://discuss.elastic.co/u/tg295)
#### Post date: [October 28, 2022, 11:10am UTC](https://discuss.elastic.co/t/unassigned-primary-replica-shard-minimise-data-loss/317393/5 "2022-10-28T11:10:03Z")
My current thinking was to follow an approach similar to: [When everything else fails. We are using Elasticsearch on a Google… | by Remco Verhoef | Medium](https://medium.com/@remco_verhoef/when-everything-else-fails-cc8a27c679d0)
Use the CheckIndex tool to see whether the shards are actually corrupt, and then proceed from there?
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### Author:  [@leandrojmp](https://discuss.elastic.co/u/leandrojmp)
#### Post date: [October 28, 2022, 2:04pm UTC](https://discuss.elastic.co/t/unassigned-primary-replica-shard-minimise-data-loss/317393/6 "2022-10-28T14:04:10Z")
> [@tg295](#):
>
> Use the CheckIndex tool to see whether the shards are actually corrupt, and then proceed from there?
You may use the `elasticsearch-shard` cli tool to see if you can recover something, here is the [documentation](https://www.elastic.co/guide/en/elasticsearch/reference/7.13/shard-tool.html).
Be aware of this warning in the documentation.
> You will lose the corrupted data when you run `elasticsearch-shard` . This tool should only be used as a last resort if there is no way to recover from another copy of the shard or restore a snapshot.
From what you shared there is not much else you can do since it appears that your index is corrupted and you may already have some level o data loss.
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### Author:  [@tg295](https://discuss.elastic.co/u/tg295)
#### Post date: [October 28, 2022, 3:52pm UTC](https://discuss.elastic.co/t/unassigned-primary-replica-shard-minimise-data-loss/317393/7 "2022-10-28T15:52:45Z")
Thank you! Wish me luck...
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### Author:  [@tg295](https://discuss.elastic.co/u/tg295)
#### Post date: [November 2, 2022, 2:38pm UTC](https://discuss.elastic.co/t/unassigned-primary-replica-shard-minimise-data-loss/317393/8 "2022-11-02T14:38:43Z")
The documentation explicitly says to "Stop Elasticsearch before running elasticsearch-shard."
Does this apply to the particular node or my entire cluster?
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### Author:  [@leandrojmp](https://discuss.elastic.co/u/leandrojmp)
#### Post date: [November 2, 2022, 2:47pm UTC](https://discuss.elastic.co/t/unassigned-primary-replica-shard-minimise-data-loss/317393/9 "2022-11-02T14:47:41Z")
> [@tg295](#):
>
> Does this apply to the particular node or my entire cluster?
Never used this command, but I would assume that it is the Elasticsearch node that has the shard you want to try to fix.
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### Author:  [@tg295](https://discuss.elastic.co/u/tg295)
#### Post date: [November 4, 2022, 10:16am UTC](https://discuss.elastic.co/t/unassigned-primary-replica-shard-minimise-data-loss/317393/10 "2022-11-04T10:16:23Z")
Due to the size of our cluster, stopping Elasticsearch / reallocating an entire node is quite an operation - do you know of any method that might allow us to address the issue without doing so? I assume not but worth an ask.. Many thanks for all your help by the way 🙂
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### Author:  [@leandrojmp](https://discuss.elastic.co/u/leandrojmp)
#### Post date: [November 4, 2022, 1:23pm UTC](https://discuss.elastic.co/t/unassigned-primary-replica-shard-minimise-data-loss/317393/11 "2022-11-04T13:23:24Z")
> [@tg295](#):
>
> do you know of any method that might allow us to address the issue without doing so?
The `elasticsearch-shard` command is already a last resort for cases like yours, and there is no guarantee that it will work, but to be able to try it you will need to shutdown this node.
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### Author:  [@tg295](https://discuss.elastic.co/u/tg295)
#### Post date: [November 4, 2022, 2:27pm UTC](https://discuss.elastic.co/t/unassigned-primary-replica-shard-minimise-data-loss/317393/12 "2022-11-04T14:27:53Z")
Ok, thanks for the info and your swift reply.
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### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [December 2, 2022, 2:28pm UTC](https://discuss.elastic.co/t/unassigned-primary-replica-shard-minimise-data-loss/317393/13 "2022-12-02T14:28:34Z")
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