---
title: "Cluster"
description: "Operate a simplyblock storage cluster on Kubernetes: request cluster actions, restart it node by node, upgrade it, and set its data placement."
source: "https://docs.simplyblock.io/latest/kubernetes/operations/cluster/"
---

# Cluster

A storage cluster is operated through its `StorageCluster` resource. A cluster-wide action is requested by setting
`spec.action`, and the Simplyblock Operator calls the control plane and reports the outcome in the status of the
resource. The topology settings of a cluster, its failure domains and its node affinity, are properties of the same
resource and are read when data placement is decided.

| Topic                                                         | Purpose                                                                           |
|---------------------------------------------------------------|-----------------------------------------------------------------------------------|
| [Storage Cluster Actions](cluster-actions.md)                 | The mechanism behind every action: requesting, executing, re-running, monitoring. |
| [Activating a Storage Cluster](activating-a-cluster.md)       | Making a cluster serve I/O when the automatic activation did not happen.          |
| [Shutting Down a Storage Cluster](shutting-down-a-cluster.md) | Suspending the whole cluster and taking all of its volumes offline.               |
| [Starting a Storage Cluster](starting-a-cluster.md)           | Bringing a suspended cluster back into service.                                   |
| [Restarting a Storage Cluster](restarting-a-cluster.md)       | Sequencing a shutdown and a start in one action.                                  |
| [Rolling Restart](rolling-restart.md)                         | Restarting every storage node of a cluster, one node at a time.                   |
| [Upgrading a Cluster](cluster-upgrade.md)                     | Upgrading the Helm chart, and rolling the storage plane node by node afterward.   |
| [Managing Failure Domains](failure-domains.md)                | Grouping storage nodes into fault groups, so that chunks are spread across them.  |
| [Configuring Node Affinity](node-affinity.md)                 | Keeping the data of a logical volume on the storage node that owns it.            |