# Extend cluster, new data nodes, identical disk space? **URL:** \ **Category:** Elasticsearch\ **Created:** [November 23, 2021, 9:44am UTC](https://discuss.elastic.co/t/extend-cluster-new-data-nodes-identical-disk-space/289931 "2021-11-23T09:44:15Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![benoitp](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/benoitp/32/97430_2.png) [@benoitp](https://discuss.elastic.co/u/benoitp)\ **Post date:** [November 23, 2021, 9:44am UTC](https://discuss.elastic.co/t/extend-cluster-new-data-nodes-identical-disk-space/289931/1 "2021-11-23T09:44:15Z")
Hello, I have a cluster with 4 data nodes, each with a storage of 4 To dedicated to the ES datas. Can i add 2 more data nodes, but only with 2 To of disk dedicated to the ES datas ? I don’t know if ES will handle this nicely. Elasticsearch 7.10. Thanks. ---
**Author:** ![DineshNaik](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/dineshnaik/32/89308_2.png) [@DineshNaik](https://discuss.elastic.co/u/DineshNaik)\ **Post date:** [November 23, 2021, 12:55pm UTC](https://discuss.elastic.co/t/extend-cluster-new-data-nodes-identical-disk-space/289931/2 "2021-11-23T12:55:33Z")
Yes, it is possible. but you need to check the total index size and your sharing strategy. Because once the new nodes are added the shard relocation will happen and there should be enough space available in the new nodes. The best practice is to use all data nodes with similar infra. (CPU,RAM,Disk etc). ---
**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:** [November 23, 2021, 8:59pm UTC](https://discuss.elastic.co/t/extend-cluster-new-data-nodes-identical-disk-space/289931/3 "2021-11-23T20:59:24Z")
Welcome to our community! 😃 What is "To"? ---
**Author:** ![DineshNaik](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/dineshnaik/32/89308_2.png) [@DineshNaik](https://discuss.elastic.co/u/DineshNaik)\ **Post date:** [November 24, 2021, 5:46am UTC](https://discuss.elastic.co/t/extend-cluster-new-data-nodes-identical-disk-space/289931/4 "2021-11-24T05:46:03Z")
might be a typo for tb , thats what i thought! ---
**Author:** ![DavidTurner](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/davidturner/32/22453_2.png) [@DavidTurner](https://discuss.elastic.co/u/DavidTurner)\ **Post date:** [November 24, 2021, 6:14am UTC](https://discuss.elastic.co/t/extend-cluster-new-data-nodes-identical-disk-space/289931/5 "2021-11-24T06:14:45Z")
Some languages (e.g. French) call bytes "octets", and thus they abbreviate it to "o" instead of "b". ---
**Author:** ![benoitp](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/benoitp/32/97430_2.png) [@benoitp](https://discuss.elastic.co/u/benoitp)\ **Post date:** [November 24, 2021, 8:20am UTC](https://discuss.elastic.co/t/extend-cluster-new-data-nodes-identical-disk-space/289931/6 "2021-11-24T08:20:08Z")
by enough space, you mean «in the cluster globally» ? How is the space managed ? Will ES allocate no more than % percent by node ? or relocation is based only on the number of shards per node ? ---
**Author:** ![DineshNaik](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/dineshnaik/32/89308_2.png) [@DineshNaik](https://discuss.elastic.co/u/DineshNaik)\ **Post date:** [November 24, 2021, 8:35am UTC](https://discuss.elastic.co/t/extend-cluster-new-data-nodes-identical-disk-space/289931/7 "2021-11-24T08:35:56Z")
_Shard allocation_ is the process of allocating shards to nodes. This can happen during initial recovery, replica allocation, rebalancing, or when nodes are added or removed. One of the main roles of the master is to decide which shards to allocate to which nodes, and when to move shards between nodes in order to rebalance the cluster. There are a number of settings available to control the shard allocation process: - [Cluster-level shard allocation settings](https://www.elastic.co/guide/en/elasticsearch/reference/current/modules-cluster.html#cluster-shard-allocation-settings) control allocation and rebalancing operations. - [Disk-based shard allocation settings](https://www.elastic.co/guide/en/elasticsearch/reference/current/modules-cluster.html#disk-based-shard-allocation) explains how Elasticsearch takes available disk space into account, and the related settings. - [Shard allocation awareness](https://www.elastic.co/guide/en/elasticsearch/reference/current/modules-cluster.html#shard-allocation-awareness) and [Forced awareness](https://www.elastic.co/guide/en/elasticsearch/reference/current/modules-cluster.html#forced-awareness) control how shards can be distributed across different racks or availability zones. - [Cluster-level shard allocation filtering](https://www.elastic.co/guide/en/elasticsearch/reference/current/modules-cluster.html#cluster-shard-allocation-filtering) allows certain nodes or groups of nodes excluded from allocation so that they can be decommissioned. Besides these, there are a few other [miscellaneous cluster-level settings](https://www.elastic.co/guide/en/elasticsearch/reference/current/modules-cluster.html#misc-cluster-settings). Refer here for more details: [Cluster-level shard allocation and routing settings | Elasticsearch Guide [7.15] | Elastic](https://www.elastic.co/guide/en/elasticsearch/reference/current/modules-cluster.html#cluster-shard-allocation-settings) ---
**Author:** ![benoitp](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/benoitp/32/97430_2.png) [@benoitp](https://discuss.elastic.co/u/benoitp)\ **Post date:** [November 24, 2021, 1:07pm UTC](https://discuss.elastic.co/t/extend-cluster-new-data-nodes-identical-disk-space/289931/8 "2021-11-24T13:07:14Z")
Thank you for this full answer, i will read all theses links. ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [December 22, 2021, 1:07pm UTC](https://discuss.elastic.co/t/extend-cluster-new-data-nodes-identical-disk-space/289931/9 "2021-12-22T13:07:34Z")
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