# Elastic search using more RAM and not release

**URL:** <https://discuss.elastic.co/t/elastic-search-using-more-ram-and-not-release/264928>\
**Category:** Elasticsearch\
**Created:** [February 20, 2021, 2:23am UTC](https://discuss.elastic.co/t/elastic-search-using-more-ram-and-not-release/264928 "2021-02-20T02:23:53Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![xgx](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/xgx/32/122246_2.png) [@xgx](https://discuss.elastic.co/u/xgx)\
**Post date:** [February 20, 2021, 2:23am UTC](https://discuss.elastic.co/t/elastic-search-using-more-ram-and-not-release/264928/1 "2021-02-20T02:23:54Z")

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Hi,  
I have a problem with elastic search uses a lot of os memory (non buff / cache).Here are some details：  
1.I am using a 64 GB Ram machine .  
2.I have allocated 26gb as ES heap size.  
3.only elasticsearch service running on machine.

After running for a while， I see that elastic search is using up most of the RAM,

 ![image](https://us1.discourse-cdn.com/elastic/original/3X/e/c/ec71be23802e349764f72663fc7d23dde17c618d.png)

Meanwhile ，Of the 26 GB heap space allocated, only 16 GB has been used up.  
I noticed that in the process mapping file / proc / PID / smaps, elastic search has applied for about 500 anonymous memory spaces with the size of 50MB.

 ![image](https://us1.discourse-cdn.com/elastic/original/3X/c/4/c4325dffeca0aab2e13e6e61a82d2852bfc926c9.png)  
Is this the behavior of elastic search or Lucene? Is it normal?

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<div class="post-metadata">

**Author:** ![warkolm](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/warkolm/32/39224_2.png) [@warkolm](https://discuss.elastic.co/u/warkolm)\
**Post date:** [February 21, 2021, 9:45pm UTC](https://discuss.elastic.co/t/elastic-search-using-more-ram-and-not-release/264928/2 "2021-02-21T21:45:52Z")

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This is the OS doing what is should do and is caching constantly used files in memory.

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**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [March 21, 2021, 9:46pm UTC](https://discuss.elastic.co/t/elastic-search-using-more-ram-and-not-release/264928/3 "2021-03-21T21:46:41Z")

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