Longhorn is an easy-to-use distributed block storage system, providing highly available persistent storage for Kubernetes. It incorporates built-in features such as incremental snapshots, backup, and backup storage in a secondary storage compatible with NFS or S3, ensuring data security within the Kubernetes cluster..
Installation requirements
Each node in the Kubernetes cluster where Longhorn is installed must meet the following requirements:
- Kubernetes: v1.21 or later, Docker: v1.13 or later, Containerd: v1.3.7 or later.
- The open-iscsi package is installed, and the iscsid service is running.
- The NFSv4 client is installed, necessary for backup and ReadWriteMany (RWX) functionality.
- Filesystem: ext4 or XFS.
- Packages: bash, curl, findmnt, grep, awk, blkid, lsblk are installed.
- Mount propagation is enabled in the cluster.
Installation consists of three steps:
- Download the Helm chart and configuration file
- Fill in the configuration file
- Install the Longhorn chart using Helm in the Kubernetes cluster
Step 1: Download the Helm chart and configuration file
For online installation, obtain the configuration file values-longhorn.yaml by executing the command:
helm repo add elma365 https://charts.elma365.tech
helm repo update
helm show values elma365/longhorn > values-longhorn.yaml
Step 2: Fill in the configuration file
Fill in the values-longhorn.yaml configuration file to install the Longhorn service..
## Longhorn settings
longhorn:
defaultSettings:
# Directory for storing data on the host
defaultDataPath: /longhorn
## Schedule replicas on nodes with existing healthy replicas of the same volume
replicaSoftAntiAffinity: true
## Automatically balance replicas upon detecting an available node
replicaAutoBalance: best-effort
ingress:
## Enable Ingress for the Longhorn UI
enabled: false
ingressClassName: ~
## Domain (FQDN) through which the Longhorn UI will be accessible
host: example.ru
## Enable encryption
tls: false
tlsSecret: elma365-onpremise-tls
csi:
## : kubelet root directory
kubeletRootDir: /var/lib/kubelet
Step 3: Install the Longhorn chart using Helm in the Kubernetes cluster
Perform the installation of the Longhorn chart online in namespace longhorn-system. The namespace will be created during installation if not created earlier.
helm upgrade --install longhorn elma365/longhorn -f values-longhorn.yaml -n longhorn-system --create-namespace
Delete the Longhorn chart using helm in the Kubernetes cluster
To enable the removal of Longhorn, set the value true for the deleting-confirmation-flag flag by executing the command Longhorn:
kubectl -n longhorn-system patch -p '{"value": "true"}' --type=merge lhs deleting-confirmation-flag
To uninstall the Longhorn chart in namespace longhorn-system, execute the command:
helm uninstall longhorn -n longhorn-system