# High IO when use replica

**URL:** <https://discuss.elastic.co/t/high-io-when-use-replica/119237>\
**Category:** Elasticsearch\
**Created:** [February 9, 2018, 12:54pm UTC](https://discuss.elastic.co/t/high-io-when-use-replica/119237 "2018-02-09T12:54:37Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![andrewliuxxx](https://avatars.discourse-cdn.com/v4/letter/a/d6d6ee/32.png) [@andrewliuxxx](https://discuss.elastic.co/u/andrewliuxxx)\
**Post date:** [February 9, 2018, 12:54pm UTC](https://discuss.elastic.co/t/high-io-when-use-replica/119237/1 "2018-02-09T12:54:37Z")

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Dear All:  
I have a ES 6.0.1 cluster with **64 machine** and 256 nodes .with about 200000 records will be indexed to ES index every second. And Some problems occur.

1. if the index has 256 shards ,0 replicas , get a normal IO util(less than 10)
2. if the index has 64 shards ,0 replicas , get a normal IO util(less than 10)
3. if the index has 32 shards ,1 replicas , get a normal IO util(less than 10)
4. if the index has 16 shards ,3 replicas , get a normal IO util(less than 10)
5. if the index has 64 shards ,1 replicas , **get an abnormal IO util(more than 50)**
6. if the index has 128 shards ,1 replicas , **get an abnormal IO util(more than 50)**
7. if the index has 32 shards ,3 replicas , **get an abnormal IO util(more than 50)**  
can anyone tell me why? thanks a lot!

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**Author:** ![andrewliuxxx](https://avatars.discourse-cdn.com/v4/letter/a/d6d6ee/32.png) [@andrewliuxxx](https://discuss.elastic.co/u/andrewliuxxx)\
**Post date:** [February 12, 2018, 8:03am UTC](https://discuss.elastic.co/t/high-io-when-use-replica/119237/2 "2018-02-12T08:03:14Z")

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6.2.0 is available ,you can try it

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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 12, 2018, 8:03am UTC](https://discuss.elastic.co/t/high-io-when-use-replica/119237/3 "2018-03-12T08:03:53Z")

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Closed on March 12, 2018, 8:03am UTC

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