# Primary Shards and Replica Shards

**URL:** <https://discuss.elastic.co/t/primary-shards-and-replica-shards/171946>\
**Category:** Elasticsearch\
**Created:** [March 12, 2019, 12:20pm UTC](https://discuss.elastic.co/t/primary-shards-and-replica-shards/171946 "2019-03-12T12:20:50Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![rahulkumar1](https://avatars.discourse-cdn.com/v4/letter/r/a4c791/32.png) [@rahulkumar1](https://discuss.elastic.co/u/rahulkumar1)\
**Post date:** [March 12, 2019, 12:20pm UTC](https://discuss.elastic.co/t/primary-shards-and-replica-shards/171946/1 "2019-03-12T12:20:50Z")

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I have three Master Nodes in a cluster: If I plan to have 1 Primary shard and two Replica shards, at any point of time how many nodes can fail without any data loss ? What would be the recommended numb er of Primary shards and replica shards ?

[[https://www.elastic.co/guide/en/elasticsearch/guide/master/\_scale\_horizontally.html#cluster-three-nodes](https://www.elastic.co/guide/en/elasticsearch/guide/master/_scale_horizontally.html#cluster-three-nodes)] As per this if we have three Master Nodes in a cluster with One Primary shard and two Replica shards each then we can afford to lose two nodes without losing any data

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**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:** [March 12, 2019, 12:47pm UTC](https://discuss.elastic.co/t/primary-shards-and-replica-shards/171946/2 "2019-03-12T12:47:46Z")

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You can lose 2 nodes without losing data, but once you lose the second node the cluster will no longer accept writes or updates if there is not a majority of master eligible nodes available.

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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:** [April 9, 2019, 12:47pm UTC](https://discuss.elastic.co/t/primary-shards-and-replica-shards/171946/3 "2019-04-09T12:47:58Z")

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Closed on April 9, 2019, 12:47pm UTC

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