Expand volume

You can expand the storage volume size of each pod.

note

Volume expansion triggers pod restart, all pods restart in the order of learner -> follower -> leader and the leader pod may change after the operation.

Before you start

Check whether the cluster status is Running. Otherwise, the following operations may fail.

kbcli cluster list mysql-cluster
>
NAME                 NAMESPACE        CLUSTER-DEFINITION        VERSION                TERMINATION-POLICY        STATUS         CREATED-TIME
mysql-cluster        default          apecloud-mysql            ac-mysql-8.0.30        Delete                    Running        Jan 29,2023 14:29 UTC+0800

Steps

1. Change configuration. There are 3 ways to apply volume expansion.

   Option 1. (Recommended) Use kbcli

   Configure the values of --components, --volume-claim-templates, and --storage, and run the command below to expand the volume.

   kbcli cluster volume-expand mysql-cluster --components="mysql" \
   --volume-claim-templates="data" --storage="2Gi"
   • --components describes the component name for volume expansion.
   • --volume-claim-templates describes the VolumeClaimTemplate names in components.
   • --storage describes the volume storage size.

   Option 2. Create an OpsRequest

   Change the value of storage according to your need and run the command below to expand the volume of a cluster.

   kubectl apply -f - <<EOF
   apiVersion: apps.kubeblocks.io/v1alpha1
   kind: OpsRequest
   metadata:
     name: ops-volume-expansion
   spec:
     clusterRef: mysql-cluster
     type: VolumeExpansion
     volumeExpansion:
     - componentName: mysql
       volumeClaimTemplates:
       - name: data
         storage: "2Gi"
   EOF

   Option 3. Change the YAML file of the cluster

   Change the value of spec.componentSpecs.volumeClaimTemplates.spec.resources in the cluster YAML file.

   spec.componentSpecs.volumeClaimTemplates.spec.resources is the storage resource information of the pod and changing this value triggers the volume expansion of a cluster.

   apiVersion: apps.kubeblocks.io/v1alpha1
   kind: Cluster
   metadata:
     name: mysql-cluster
     namespace: default
   spec:
     clusterDefinitionRef: apecloud-mysql
     clusterVersionRef: ac-mysql-8.0.30
     componentSpecs:
     - name: mysql
       componentDefRef: mysql
       replicas: 1
       volumeClaimTemplates:
       - name: data
         spec:
           accessModes:
             - ReadWriteOnce
           resources:
             requests:
               storage: 1Gi # Change the volume storage size.
     terminationPolicy: Halt

2. Validate the volume expansion operation.

   kbcli cluster list mysql-cluster
   >
   NAME                 NAMESPACE        CLUSTER-DEFINITION        VERSION                  TERMINATION-POLICY        STATUS                 CREATED-TIME
   mysql-cluster        default          apecloud-mysql            ac-mysql-8.0.30          Delete                    VolumeExpanding        Jan 29,2023 14:35 UTC+0800
   • STATUS=VolumeExpanding: it means the volume expansion is in progress.
   • STATUS=Running: it means the volume expansion operation has been applied.

3. Check whether the corresponding resources change.

   kbcli cluster describe mysql-cluster