Unexpected file read error while reading index

[tropically (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 :

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

[DavidTurner]

@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 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.

[tropically (Div)]

Thanks David for your response.