# Cluster Rebalancing

**URL:** <https://discuss.elastic.co/t/cluster-rebalancing/264303>\
**Category:** Elasticsearch\
**Created:** [February 15, 2021, 11:38am UTC](https://discuss.elastic.co/t/cluster-rebalancing/264303 "2021-02-15T11:38:58Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![cwiechmann](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/cwiechmann/32/80908_2.png) [@cwiechmann](https://discuss.elastic.co/u/cwiechmann)\
**Post date:** [February 15, 2021, 11:38am UTC](https://discuss.elastic.co/t/cluster-rebalancing/264303/1 "2021-02-15T11:38:58Z")

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Hi All,

I'm using ILM policies and as part of the Warm-Phase indices should be shrinked. As you know, for that all of the shards of an index must be reallocated to a single node, which unfortunately quite often fails. It fails for the following error returned by: `GET /_cluster/allocation/explain`

```auto
_the node is above the low watermark cluster setting [cluster.routing.allocation.disk.watermark.low=85%], using more disk space than the maximum allowed [85.0%]_

```

The point is, that I have plenty of disk space available on other nodes, but due to [disk allocation rules](https://www.elastic.co/guide/en/elasticsearch/reference/master/modules-cluster.html#disk-based-shard-allocation), Elasticsearch does not start to reallocate shards, just because the low disk watermark is reached.

This is annoying, as it stops the shrink process quite often and I have to manually reallocate shards away from the Low-Disk-Watermark node.

Do you have any recommendations how to make this process more stable? Perhaps telling Elasticsearch to start re-balancing already on Low-Disk-Watermark.

Thanks!  
Chris

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<div class="post-metadata">

**Author:** ![cwiechmann](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/cwiechmann/32/80908_2.png) [@cwiechmann](https://discuss.elastic.co/u/cwiechmann)\
**Post date:** [February 15, 2021, 12:39pm UTC](https://discuss.elastic.co/t/cluster-rebalancing/264303/2 "2021-02-15T12:39:17Z")

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As a workaround I put the High-Disk watermark very close to the Low-disk watermark to force Elasticsearch to move shards away from the Low-Disk-Node. This helped, but I'm open for any other recommendation.

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**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 15, 2021, 10:40pm UTC](https://discuss.elastic.co/t/cluster-rebalancing/264303/3 "2021-02-15T22:40:17Z")

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Can you increase the watermarks?

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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 15, 2021, 10:40pm UTC](https://discuss.elastic.co/t/cluster-rebalancing/264303/4 "2021-03-15T22:40:28Z")

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