OpenEBS

Overview

OpenEBS (Elastic Block Store) is an open-source platform that enables cloud-native, local or distributed persistent volume (PV) storage for Kubernetes. It is a platform-agnostic alternative to Amazon Elastic Block Store.

For more about OpenEBS, see the official OpenEBS documentation, particularly the Prerequisites.

Planning your deployment

OpenEBS supports several types of volumes. For Aerospike clusters, use Logical Volume Manager (LVM) local PV storage volumes. OpenEBS processes nodes with LVM set up on them to create storage pools, enabling dynamic storage allocation and aggregation across devices.

Note

Aerospike strongly discourages using replicated volumes. Aerospike already implements replication at the application level, and the additional replication could severely impact performance and reliability.

OpenEBS removed support for Local PV (Device) volumes in version 3.5. See previous versions of this AKO documentation page for instructions on setting up these legacy volumes.

With an LVM local PV, Aerospike can create any number of persistent volume claims (PVCs). The aggregate size should be less than the size of the volume group.

Install OpenEBS with Helm

1. Run the following commands to install OpenEBS on your Kubernetes cluster with default settings.

   helm repo add openebs https://openebs.github.io/openebs \
   && helm repo update \
   && helm install openebs --namespace openebs openebs/openebs --set engines.replicated.mayastor.enabled=false --create-namespace

2. Run get pod to see one lvm-controller pod and lvm-node daemonset running on the nodes. You may see more pods depending on your setup.

   % kubectl get pod -n openebs
   
   NAME                                             READY   STATUS    RESTARTS     AGE
   openebs-localpv-provisioner-6bd66f8598-4zt77     1/1     Running   2 (8d ago)   26d
   openebs-lvm-localpv-controller-6bbd64786-pt2r7   5/5     Running   0            26d
   openebs-lvm-localpv-node-2bnd5                   2/2     Running   0            26d
   openebs-lvm-localpv-node-7d2mg                   2/2     Running   0            26d
   openebs-lvm-localpv-node-gz5wv                   2/2     Running   0            26d

The OpenEBS installation documentation includes information about customizing these settings.

Set up an LVM local PV

The following steps guide you through a default setup process. See the OpenEBS LVM Installation documentation for a full list of options.

1. Run lvs to list all volumes and verify that you have lvm2 installed.

2. Use vgcreate to set up a volume group that will be used by the LVM Driver for provisioning the volumes.

   The following example creates two volumes, then groups them into the lvmvg volume group.

   sudo pvcreate /dev/sdb1
     Physical volume "/dev/sdb1" successfully created.
   sudo pvcreate /dev/sdc1
     Physical volume "/dev/sdc1" successfully created.
   sudo vgcreate lvmvg /dev/sdb1 /dev/sdc1
     Volume group "lvmvg" successfully created

3. Create a storage class with the provisioner field set to local.csi.openebs.io.

   apiVersion: storage.k8s.io/v1
   kind: StorageClass
   metadata:
     name: openebs-lvmpv
   parameters:
     storage: "lvm"
     volgroup: "lvmvg"
   provisioner: local.csi.openebs.io
   volumeBindingMode: WaitForFirstConsumer

4. Install an Aerospike cluster by setting storageClass to the storage class you set up in the previous step to provision a local volume PVC.

       volumes:
         - name: workdir
           aerospike:
             path: /opt/aerospike
           source:
             persistentVolume:
               storageClass: ssd
               volumeMode: Filesystem
               size: 1Gi
         - name: ns1
           aerospike:
             path: /test/dev/xvdf1
           source:
             persistentVolume:
               storageClass: openebs-lvmpv # Storage class name
               volumeMode: Block
               size: 5Gi

You should now have a working Aerospike cluster with an OpenEBS backed local storage.