# Unexpected file read error while reading index

**URL:** https://discuss.elastic.co/t/unexpected-file-read-error-while-reading-index/288795
**Category:** Elasticsearch
**Created:** [November 9, 2021, 4:35pm UTC](https://discuss.elastic.co/t/unexpected-file-read-error-while-reading-index/288795 "2021-11-09T16:35:46Z")
**Posts on this page:** 4
**Page:** 1

<div class="post-metadata">

### Author: ![tropically](https://avatars.discourse-cdn.com/v4/letter/t/ee59a6/32.png) [@tropically](https://discuss.elastic.co/u/tropically)
#### Post date: [November 9, 2021, 4:35pm UTC](https://discuss.elastic.co/t/unexpected-file-read-error-while-reading-index/288795/1 "2021-11-09T16:35:46Z")

</div>

Hi  
We are running elastisearch on Openshift. Currently there are 3 nodes configured.

We received the below error on one of the 3 nodes that we have :

```auto
ElasticsearchException[failed to load metadata]; nested: CorruptIndexException[Unexpected file read error while reading index. (resource=BufferedChecksumIndexInput(SimpleFSIndexInput(path=\"/usr/share/elasticsearch/data/nodes/0/_state/segments_t4z

```

My Questions are

On removing the file, "/usr/share/Elasticsearch/data/nodes/0/\_state/segments\_t4z" the pod is able to come back up without errors.  
What is the "segments\_t4z" file for? Is there any loss of data , associated with removing this file?

TIA  
Div

---

<div class="post-metadata">

### Author: ![DavidTurner](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/davidturner/32/22453_2.png) [@DavidTurner](https://discuss.elastic.co/u/DavidTurner)
#### Post date: [November 9, 2021, 4:58pm UTC](https://discuss.elastic.co/t/unexpected-file-read-error-while-reading-index/288795/2 "2021-11-09T16:58:21Z")

</div>

> [@tropically](#):
>
> Is there any loss of data , associated with removing this file?

Maybe, but it's not possible to answer this reliably. See [these docs](https://www.elastic.co/guide/en/elasticsearch/reference/current/modules-node.html#data-path) for more details:

> **WARNING** : Don’t modify anything within the data directory or run processes that might interfere with its contents. If something other than Elasticsearch modifies the contents of the data directory, then Elasticsearch may fail, reporting corruption or other data inconsistencies, or may appear to work correctly having silently lost some of your data.

---

<div class="post-metadata">

### Author: ![tropically](https://avatars.discourse-cdn.com/v4/letter/t/ee59a6/32.png) [@tropically](https://discuss.elastic.co/u/tropically)
#### Post date: [November 9, 2021, 7:23pm UTC](https://discuss.elastic.co/t/unexpected-file-read-error-while-reading-index/288795/3 "2021-11-09T19:23:58Z")

</div>

Thanks David for your response.

---

<div class="post-metadata">

### Author: ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)
#### Post date: [December 7, 2021, 7:24pm UTC](https://discuss.elastic.co/t/unexpected-file-read-error-while-reading-index/288795/4 "2021-12-07T19:24:14Z")

</div>

This topic was automatically closed 28 days after the last reply. New replies are no longer allowed.