# UNASSIGNED ALLOCATION\_FAILED failed shard on node \[t8d551UUTkKLOjukvvsKeA\]: shard failure, reason \[error sending files\], failure CorruptIndexException\[checksum failed (hardware problem?) : expected=1udzqw9 actual=1i6i2wk (resource=name \[\_7y8\_Lu

**URL:** <https://forum.opensearch.org/t/unassigned-allocation-failed-failed-shard-on-node-t8d551uutkklojukvvskea-shard-failure-reason-error-sending-files-failure-corruptindexexception-checksum-failed-hardware-problem-expected-1udzqw9-actual-1i6i2wk-resource-name-7y8-lu/17323>\
**Category:** OpenSearch\
**Tags:** discuss\
**Created:** [January 4, 2024, 6:13am UTC](https://forum.opensearch.org/t/unassigned-allocation-failed-failed-shard-on-node-t8d551uutkklojukvvskea-shard-failure-reason-error-sending-files-failure-corruptindexexception-checksum-failed-hardware-problem-expected-1udzqw9-actual-1i6i2wk-resource-name-7y8-lu/17323 "2024-01-04T06:13:52Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![sanjujayan](https://avatars.discourse-cdn.com/v4/letter/s/7ba0ec/32.png) [@sanjujayan](https://forum.opensearch.org/u/sanjujayan)\
**Post date:** [January 4, 2024, 6:13am UTC](https://forum.opensearch.org/t/unassigned-allocation-failed-failed-shard-on-node-t8d551uutkklojukvvskea-shard-failure-reason-error-sending-files-failure-corruptindexexception-checksum-failed-hardware-problem-expected-1udzqw9-actual-1i6i2wk-resource-name-7y8-lu/17323/1 "2024-01-04T06:13:52Z")

</div>

**Versions** (relevant - OpenSearch/Dashboard/Server OS/Browser): 2.1

**Describe the issue** : index crashing

**Configuration** : none

**Relevant Logs or Screenshots** :

UNASSIGNED ALLOCATION\_FAILED failed shard on node [t8d551UUTkKLOjukvvsKeA]: shard failure, reason [error sending files], failure CorruptIndexException[checksum failed (hardware problem?) : expected=1udzqw9 actual=1i6i2wk (resource=name [\_7y8\_Lucene90\_0.tim], length [299485807], checksum [1udzqw9], writtenBy [9.6.0]) (resource=VerifyingIndexOutput(\_7y8\_Lucene90\_0.tim))]

---

<div class="post-metadata">

**Author:** ![vnovotny98](https://avatars.discourse-cdn.com/v4/letter/v/53a042/32.png) [@vnovotny98](https://forum.opensearch.org/u/vnovotny98)\
**Post date:** [January 4, 2024, 7:20pm UTC](https://forum.opensearch.org/t/unassigned-allocation-failed-failed-shard-on-node-t8d551uutkklojukvvskea-shard-failure-reason-error-sending-files-failure-corruptindexexception-checksum-failed-hardware-problem-expected-1udzqw9-actual-1i6i2wk-resource-name-7y8-lu/17323/2 "2024-01-04T19:20:47Z")

</div>

I think that you need to provide more info:

- how many nodes you have
- deployment (self - on-prem, aws, managed)
- what is your configuration (opensearch.yml)
- where you store data

I have never seen this error