New to KubeDB? Please start here.
RabbitMQ Standalone Volume Expansion
This guide will show you how to use KubeDB Ops-manager operator to expand the volume of a RabbitMQ database.
Before You Begin
At first, you need to have a Kubernetes cluster, and the
kubectlcommand-line tool must be configured to communicate with your cluster.You must have a
StorageClassthat supports volume expansion.Install
KubeDBProvisioner and Ops-manager operator in your cluster following the steps here.You should be familiar with the following
KubeDBconcepts:
To keep everything isolated, we are going to use a separate namespace called demo throughout this tutorial.
$ kubectl create ns demo
namespace/demo created
Note: The yaml files used in this tutorial are stored in docs/examples/RabbitMQ folder in GitHub repository kubedb/docs.
Expand Volume of RabbitMQ Database
Here, we are going to deploy a RabbitMQ standalone using a supported version by KubeDB operator. Then we are going to apply RabbitMQOpsRequest to expand its volume.
Prepare RabbitMQ Standalone Database
At first verify that your cluster has a storage class, that supports volume expansion. Let’s check,
$ kubectl get storageclass
NAME PROVISIONER RECLAIMPOLICY VOLUMEBINDINGMODE ALLOWVOLUMEEXPANSION AGE
standard (default) kubernetes.io/gce-pd Delete Immediate true 2m49s
We can see from the output the standard storage class has ALLOWVOLUMEEXPANSION field as true. So, this storage class supports volume expansion. We can use it.
Now, we are going to deploy a RabbitMQ standalone database with version 3.13.2.
Deploy RabbitMQ standalone
In this section, we are going to deploy a RabbitMQ standalone database with 1GB volume. Then, in the next section we will expand its volume to 2GB using RabbitMQOpsRequest CRD. Below is the YAML of the RabbitMQ CR that we are going to create,
apiVersion: kubedb.com/v1alpha2
kind: RabbitMQ
metadata:
name: rm-standalone
namespace: demo
spec:
version: "3.13.2"
storageType: Durable
storage:
storageClassName: "standard"
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 1Gi
Let’s create the RabbitMQ CR we have shown above,
$ kubectl create -f https://github.com/kubedb/docs/raw/v2025.3.24/docs/examples/RabbitMQ/volume-expansion/rm-standalone.yaml
RabbitMQ.kubedb.com/rm-standalone created
Now, wait until rm-standalone has status Ready. i.e,
$ kubectl get rm -n demo
NAME VERSION STATUS AGE
rm-standalone 3.13.2 Ready 2m53s
Let’s check volume size from PetSet, and from the persistent volume,
$ kubectl get petset -n demo rm-standalone -o json | jq '.spec.volumeClaimTemplates[].spec.resources.requests.storage'
"1Gi"
$ kubectl get pv -n demo
NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE
pvc-d0b07657-a012-4384-862a-b4e437774287 1Gi RWO Delete Bound demo/datadir-rm-standalone-0 standard 49s
You can see the PetSet has 1GB storage, and the capacity of the persistent volume is also 1GB.
We are now ready to apply the RabbitMQOpsRequest CR to expand the volume of this database.
Volume Expansion
Here, we are going to expand the volume of the standalone database.
Create RabbitMQOpsRequest
In order to expand the volume of the database, we have to create a RabbitMQOpsRequest CR with our desired volume size. Below is the YAML of the RabbitMQOpsRequest CR that we are going to create,
apiVersion: ops.kubedb.com/v1alpha1
kind: RabbitMQOpsRequest
metadata:
name: rmops-volume-exp-standalone
namespace: demo
spec:
type: VolumeExpansion
databaseRef:
name: rm-standalone
volumeExpansion:
node: 2Gi
mode: Online
Here,
spec.databaseRef.namespecifies that we are performing volume expansion operation onrm-standalonedatabase.spec.typespecifies that we are performingVolumeExpansionon our database.spec.volumeExpansion.standalonespecifies the desired volume size.spec.volumeExpansion.modespecifies the desired volume expansion mode(OnlineorOffline).
During Online VolumeExpansion KubeDB expands volume without pausing database object, it directly updates the underlying PVC. And for Offline volume expansion, the database is paused. The Pods are deleted and PVC is updated. Then the database Pods are recreated with updated PVC.
Let’s create the RabbitMQOpsRequest CR we have shown above,
$ kubectl apply -f https://github.com/kubedb/docs/raw/v2025.3.24/docs/examples/rabbitmq/volume-expansion/rmops-volume-exp-standalone.yaml
rabbitmqopsrequest.ops.kubedb.com/rmops-volume-exp-standalone created
Verify RabbitMQ Standalone volume expanded successfully
If everything goes well, KubeDB Ops-manager operator will update the volume size of RabbitMQ object and related StatefulSets and Persistent Volume.
Let’s wait for RabbitMQOpsRequest to be Successful. Run the following command to watch RabbitMQOpsRequest CR,
$ kubectl get rabbitmqopsrequest -n demo
NAME TYPE STATUS AGE
rmops-volume-exp-standalone VolumeExpansion Successful 75s
We can see from the above output that the RabbitMQOpsRequest has succeeded. If we describe the RabbitMQOpsRequest we will get an overview of the steps that were followed to expand the volume of the database.
$ kubectl describe rabbitmqopsrequest -n demo rmops-volume-exp-standalone
Name: rmops-volume-exp-standalone
Namespace: demo
Labels: <none>
Annotations: API Version: ops.kubedb.com/v1alpha1
Kind: RabbitMQOpsRequest
Metadata:
Creation Timestamp: 2020-08-25T17:48:33Z
Finalizers:
kubedb.com
Generation: 1
Resource Version: 72899
Self Link: /apis/ops.kubedb.com/v1alpha1/namespaces/demo/rabbitmqopsrequest/rmops-volume-exp-standalone
UID: 007fe35a-25f6-45e7-9e85-9add488b2622
Spec:
Database Ref:
Name: rm-standalone
Type: VolumeExpansion
Volume Expansion:
Standalone: 2Gi
Status:
Conditions:
Last Transition Time: 2020-08-25T17:48:33Z
Message: RabbitMQ ops request is being processed
Observed Generation: 1
Reason: Scaling
Status: True
Type: Scaling
Last Transition Time: 2020-08-25T17:50:03Z
Message: Successfully updated Storage
Observed Generation: 1
Reason: VolumeExpansion
Status: True
Type: VolumeExpansion
Last Transition Time: 2020-08-25T17:50:03Z
Message: Successfully Resumed RabbitMQ: rm-standalone
Observed Generation: 1
Reason: ResumeDatabase
Status: True
Type: ResumeDatabase
Last Transition Time: 2020-08-25T17:50:03Z
Message: Successfully completed the modification process
Observed Generation: 1
Reason: Successful
Status: True
Type: Successful
Observed Generation: 1
Phase: Successful
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal VolumeExpansion 29s KubeDB Ops-manager operator Successfully Updated Storage
Normal ResumeDatabase 29s KubeDB Ops-manager operator Resuming RabbitMQ
Normal ResumeDatabase 29s KubeDB Ops-manager operator Successfully Resumed RabbitMQ
Normal Successful 29s KubeDB Ops-manager operator Successfully Scaled Database
Now, we are going to verify from the Statefulset, and the Persistent Volume whether the volume of the standalone database has expanded to meet the desired state, Let’s check,
$ kubectl get petset -n demo rm-standalone -o json | jq '.spec.volumeClaimTemplates[].spec.resources.requests.storage'
"2Gi"
$ kubectl get pv -n demo
NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE
pvc-d0b07657-a012-4384-862a-b4e437774287 2Gi RWO Delete Bound demo/datadir-mg-standalone-0 standard 4m29s
The above output verifies that we have successfully expanded the volume of the RabbitMQ standalone database.
Cleaning Up
To clean up the Kubernetes resources created by this tutorial, run:
kubectl delete rm -n demo rm-standalone
kubectl delete rabbitmqopsrequest -n demo rmops-volume-exp-standalone