---
title: Min Master Node Less Than Quorum
description: Describes what AutoOps detects and surfaces with the Min Master Node Less Than Quorum insight: The minimum_master_nodes setting is lower than a safe majority of master-eligible nodes.
url: https://docs-v3-preview.elastic.dev/elastic/autoops-insights/tree/main/elasticsearch/min_master_node_less_than_quorum
products:
  - Elastic Cloud Enterprise
  - Elastic Cloud Hosted
  - Elastic Cloud on Kubernetes
  - Elasticsearch
applies_to:
  - Elastic Cloud Hosted: Generally available
  - Elastic Cloud on Kubernetes: Generally available
  - Elastic Cloud Enterprise: Generally available
  - Self-managed Elastic deployments: Generally available
---

# Min Master Node Less Than Quorum
The minimum_master_nodes setting is lower than a safe majority of master-eligible nodes. That increases split-brain risk if parts of the cluster partition and form separate clusters.
<note>
  For a complete list of insights, refer to [AutoOps insights](https://docs-v3-preview.elastic.dev/elastic/autoops-insights/tree/main/elasticsearch).
</note>


## Insight details


| Field     | Value                                       |
|-----------|---------------------------------------------|
| Component | Elasticsearch                               |
| Severity  | High                                        |
| Scope     | Cluster                                     |
| Domains   | configuration, high-availability, stability |


## Example: What you might see in AutoOps

The following is an example of what you might see when this insight is triggered. Real insights use live data and links from your deployment or cluster.

### The minimum_master_nodes setting is less than needed for a quorum


#### What was detected

Number of nodes with the master role: 12.
Minimum master nodes current settings: es-data-01

#### Recommendations

<note>
  AutoOps shows different recommendations depending on how their conditions match your deployment or cluster.
</note>

<dropdown title="Set minimum master nodes quorum">
  **Condition**: Always shown for this insight.Set `discovery.zen.minimum_master_nodes` to 2 in each node's config, then rolling-restart master-eligible nodes so the quorum takes effect.
</dropdown>


#### Background and impact

Impact: The cluster is at risk of splitting into multiple clusters — split brain. This could cause data loss and data corruption.
The value in this setting should be 50% of the number of master eligible nodes rounded up to the nearest integer. If it is not set correctly, nodes could form a separate cluster independent of the primary cluster if they disconnect from it for any reason.