# Reindex find different storage size

**URL:** <https://discuss.elastic.co/t/reindex-find-different-storage-size/360045>\
**Category:** Elasticsearch\
**Created:** [May 23, 2024, 7:44am UTC](https://discuss.elastic.co/t/reindex-find-different-storage-size/360045 "2024-05-23T07:44:00Z")\
**Posts on this page:** 6\
**Page:** 1

<div class="post-metadata">

**Author:** ![Frances\_Chu](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/frances_chu/32/127298_2.png) [@Frances\_Chu](https://discuss.elastic.co/u/Frances_Chu)\
**Post date:** [May 23, 2024, 7:44am UTC](https://discuss.elastic.co/t/reindex-find-different-storage-size/360045/1 "2024-05-23T07:44:00Z")

</div>

i got 2 index: index\_A with 10 docs indexB with 4 docs

I try to

1. reindex index\_A and index\_B to index\_C
2. reindex index\_A and index\_B to index\_D  
with no error message

I found both index\_C and index\_D got 14 docs, expected  
but the storage size of the index\_C and index\_D is not the same.

Is it normal? Why?

 ![size](https://us1.discourse-cdn.com/elastic/original/3X/0/4/04f124dcfc53c4e18e8f19d033af2b6cb99920d0.png)

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<div class="post-metadata">

**Author:** ![Christian\_Dahlqvist](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/christian_dahlqvist/32/4617_2.png) [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)\
**Post date:** [May 23, 2024, 8:05am UTC](https://discuss.elastic.co/t/reindex-find-different-storage-size/360045/2 "2024-05-23T08:05:03Z")

</div>

There are several factors that can influence storage size so the small differences you are seeing for these tiny data volumes is nothing I would be worried about. Assuming the data ingested is exactly the same, differences in the mappings of the indices will make a difference. It is also important to check if the number of segments differ. For an accurate size comparison always make sure you forcemerge down to a single segment.

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<div class="post-metadata">

**Author:** ![Frances\_Chu](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/frances_chu/32/127298_2.png) [@Frances\_Chu](https://discuss.elastic.co/u/Frances_Chu)\
**Post date:** [May 23, 2024, 9:10am UTC](https://discuss.elastic.co/t/reindex-find-different-storage-size/360045/3 "2024-05-23T09:10:47Z")

</div>

Thanks for your reply.

I try to

```auto
POST /indexName/_forcemerge

```

no help. The size is also different. But I checked there is no missing data.

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<div class="post-metadata">

**Author:** ![Christian\_Dahlqvist](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/christian_dahlqvist/32/4617_2.png) [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)\
**Post date:** [May 23, 2024, 9:15am UTC](https://discuss.elastic.co/t/reindex-find-different-storage-size/360045/4 "2024-05-23T09:15:22Z")

</div>

You need to specify the max number of segments:

`POST /indexName/_forcemerge?max_num_segments=1`

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<div class="post-metadata">

**Author:** ![Frances\_Chu](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/frances_chu/32/127298_2.png) [@Frances\_Chu](https://discuss.elastic.co/u/Frances_Chu)\
**Post date:** [May 23, 2024, 9:27am UTC](https://discuss.elastic.co/t/reindex-find-different-storage-size/360045/5 "2024-05-23T09:27:41Z")

</div>

Big thx.

No luck. after forecemerge the storage size is also different.

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<div class="post-metadata">

**Author:** ![Christian\_Dahlqvist](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/christian_dahlqvist/32/4617_2.png) [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)\
**Post date:** [May 23, 2024, 9:33am UTC](https://discuss.elastic.co/t/reindex-find-different-storage-size/360045/6 "2024-05-23T09:33:07Z")

</div>

The difference you are seeing is IMHO really irrelevant, so I do not understand why you are concerned by it. Not sure whether the order documents are indexed may cause small differences in the size of files and efficiency of compression.