Longhorn

https://longhorn.io/docs/1.11.0/
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### Preflight Installation Output Example

Source: https://longhorn.io/docs/1.11.0/deploy/install

Example output showing the results of the preflight installation command.

```text
INFO[2025-03-11T08:17:57+08:00] Initializing preflight installer
INFO[2025-03-11T08:17:57+08:00] Cleaning up preflight installer
INFO[2025-03-11T08:17:57+08:00] Running preflight installer
INFO[2025-03-11T08:17:57+08:00] Installing dependencies with package manager
INFO[2025-03-11T08:18:28+08:00] Installed dependencies with package manager
INFO[2025-03-11T08:18:28+08:00] Cleaning up preflight installer
INFO[2025-03-11T08:18:28+08:00] Completed preflight installer. Use 'longhornctl check preflight' to check the result.
```

--------------------------------

### Example Installation Output

Source: https://longhorn.io/docs/1.11.0/deploy/install/install-with-argocd

Sample output showing running Longhorn pods.

```text
NAME                                                READY   STATUS    RESTARTS   AGE
longhorn-ui-b7c844b49-w25g5                         1/1     Running   0          2m41s
longhorn-manager-pzgsp                              1/1     Running   0          2m41s
longhorn-driver-deployer-6bd59c9f76-lqczw           1/1     Running   0          2m41s
longhorn-csi-plugin-mbwqz                           2/2     Running   0          100s
csi-snapshotter-588457fcdf-22bqp                    1/1     Running   0          100s
csi-snapshotter-588457fcdf-2wd6g                    1/1     Running   0          100s
csi-provisioner-869bdc4b79-mzrwf                    1/1     Running   0          101s
csi-provisioner-869bdc4b79-klgfm                    1/1     Running   0          101s
csi-resizer-6d8cf5f99f-fd2ck                        1/1     Running   0          101s
csi-provisioner-869bdc4b79-j46rx                    1/1     Running   0          101s
csi-snapshotter-588457fcdf-bvjdt                    1/1     Running   0          100s
csi-resizer-6d8cf5f99f-68cw7                        1/1     Running   0          101s
csi-attacher-7bf4b7f996-df8v6                       1/1     Running   0          101s
csi-attacher-7bf4b7f996-g9cwc                       1/1     Running   0          101s
csi-attacher-7bf4b7f996-8l9sw                       1/1     Running   0          101s
csi-resizer-6d8cf5f99f-smdjw                        1/1     Running   0          101s
instance-manager-b34d5db1fe1e2d52bcfb308be3166cfc   1/1     Running   0          114s
engine-image-ei-df38d2e5-cv6nc                      1/1     Running   0          114s
```

--------------------------------

### Install Preflight Dependencies

Source: https://longhorn.io/docs/1.11.0/deploy/install

Executes the install sub-command to set up preflight dependencies.

```bash
./longhornctl install preflight
```

--------------------------------

### Complete fleet.yaml Example

Source: https://longhorn.io/docs/1.11.0/deploy/install/install-with-fleet

A consolidated example of a fleet.yaml file for Longhorn deployment.

```yaml
defaultNamespace: longhorn-system
helm:
  repo: https://charts.longhorn.io
  chart: longhorn
  version: v1.11.0
  releaseName: longhorn
diff:
  comparePatches:
  - apiVersion: apiextensions.k8s.io/v1
    kind: CustomResourceDefinition
    name: engineimages.longhorn.io
    operations:
    - {"op": "replace", "path": "/status"}
  - apiVersion: apiextensions.k8s.io/v1
    kind: CustomResourceDefinition
    name: nodes.longhorn.io
    operations:
    - {"op": "replace", "path": "/status"}
  - apiVersion: apiextensions.k8s.io/v1
    kind: CustomResourceDefinition
    name: volumes.longhorn.io
    operations:
    - {"op": "replace", "path": "/status"}
```

--------------------------------

### Install Cryptsetup

Source: https://longhorn.io/docs/1.11.0/deploy/install

Commands to install the cryptsetup utility for disk encryption support.

```bash
apt-get install cryptsetup
```

```bash
yum install cryptsetup
```

```bash
zypper install cryptsetup
```

--------------------------------

### Install open-iscsi on SUSE and openSUSE

Source: https://longhorn.io/docs/1.11.0/deploy/install

Use these commands to install and start the iscsid service on SUSE-based systems.

```bash
zypper install open-iscsi
systemctl enable iscsid
systemctl start iscsid

```

--------------------------------

### Longhorn service output example

Source: https://longhorn.io/docs/1.11.0/deploy/accessing-the-ui

Example output showing the ClusterIP for the longhorn-frontend service.

```text
NAME                TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)    AGE
longhorn-backend    ClusterIP   10.20.248.250   <none>        9500/TCP   58m
longhorn-frontend   ClusterIP   10.20.245.110   <none>        80/TCP     58m
```

--------------------------------

### Verify Installation Resources

Source: https://longhorn.io/docs/1.11.0/deploy/install/install-with-helm-controller

Commands to check the status of the installation job, pods, and HelmChart resources.

```bash
$ kubectl get jobs
NAME                            COMPLETIONS   DURATION   AGE
helm-install-longhorn-install   0/1           8s         8s

$ kubectl get pods
NAME                                  READY   STATUS      RESTARTS   AGE
helm-install-longhorn-install-lngm8   0/1     Completed   0          25s

$ kubectl get helmcharts
NAME               JOB                     CHART      TARGETNAMESPACE   VERSION   REPO                         HELMVERSION   BOOTSTRAP
longhorn-install   helm-install-longhorn   longhorn   longhorn-system   v1.11.0    https://charts.longhorn.io
```

--------------------------------

### Troubleshoot Debian Kernel Module Installation

Source: https://longhorn.io/docs/1.11.0/v2-data-engine/troubleshooting

Example of a failed installation command and the subsequent successful installation using a specific package version.

```bash
apt install -y linux-modules-extra-`uname -r`
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Package linux-modules-extra-5.15.0-67-generic is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Package 'linux-modules-extra-5.15.0-67-generic' has no installation candidate
```

```bash
apt update -y
apt install -y linux-modules-extra-5.15.0-76-generic
```

--------------------------------

### Installation and Preflight Commands

Source: https://longhorn.io/docs/1.11.0/advanced-resources/longhornctl

Commands used for setting up dependencies and verifying system readiness.

```bash
longhornctl install preflight
```

```bash
longhornctl check preflight
```

--------------------------------

### Backup Configuration Example

Source: https://longhorn.io/docs/1.11.0/advanced-resources/data-recovery/recover-without-system

Example content of a backup.cfg file used to identify backup and volume names.

```json
{"Name":"backup-72bcbdad913546cf","VolumeName":"volume_1","SnapshotName":"79758033-a670-4724-906f-41921f53c475"}
```

--------------------------------

### Verification Example

Source: https://longhorn.io/docs/1.11.0/deploy/accessing-the-ui/longhorn-ingress-traefik

Demonstrates the full workflow from secret creation to verifying access with curl.

```bash
$ USER=foo; PASSWORD=bar; echo "${USER}:$(openssl passwd -stdin -apr1 <<< ${PASSWORD})" > auth
$ kubectl -n longhorn-system create secret generic basic-auth --from-file=auth
secret/basic-auth created

# (After applying middlewares and ingress manifests)

$ kubectl -n longhorn-system get ingress
NAME               CLASS     HOSTS   ADDRESS      PORTS   AGE
longhorn-ingress   traefik   * 10.0.2.15    80      15s

$ curl -I http://10.0.2.15/
HTTP/1.1 401 Unauthorized
Www-Authenticate: Basic realm="traefik"

$ curl -u foo:bar -I http://10.0.2.15/
HTTP/1.1 200 OK
```

--------------------------------

### Preflight Check Output Example

Source: https://longhorn.io/docs/1.11.0/deploy/install

Example output showing the results of the preflight check command.

```text
INFO[2024-01-01T00:00:01Z] Initializing preflight checker
INFO[2024-01-01T00:00:01Z] Cleaning up preflight checker
INFO[2024-01-01T00:00:01Z] Running preflight checker
INFO[2024-01-01T00:00:02Z] Retrieved preflight checker result:
worker1:
  info:
  - Service iscsid is running
  - NFS4 is supported
  - Package nfs-common is installed
  - Package open-iscsi is installed
  warn:
  - multipathd.service is running. Please refer to https://longhorn.io/kb/troubleshooting-volume-with-multipath/ for more information.
worker2:
  info:
  - Service iscsid is running
  - NFS4 is supported
  - Package nfs-common is not installed
  - Package open-iscsi is installed
```

--------------------------------

### Example IOMMU Output

Source: https://longhorn.io/docs/1.11.0/v2-data-engine/features/interrupt-mode

Sample output indicating that IOMMU is correctly enabled on the system.

```text
/sys/kernel/iommu_groups/0/devices/0000:e6:0b.1
/sys/kernel/iommu_groups/1/devices/0000:34:0a.6
/sys/kernel/iommu_groups/2/devices/0000:a0:00.0
```

--------------------------------

### Install Argo CD

Source: https://longhorn.io/docs/1.11.0/deploy/install/install-with-argocd

Commands to create the argocd namespace and apply the core installation manifests.

```bash
kubectl create namespace argocd
kubectl apply -n argocd -f https://raw.githubusercontent.com/argoproj/argo-cd/stable/manifests/core-install.yaml
```

--------------------------------

### Install Preflight Dependencies

Source: https://longhorn.io/docs/1.11.0/v2-data-engine/quick-start

Install required preflight dependencies using the longhornctl tool.

```bash
master:~# ./longhornctl install preflight --enable-spdk
INFO[2024-01-01T00:00:03Z] Initializing preflight installer
INFO[2024-01-01T00:00:03Z] Cleaning up preflight installer
INFO[2024-01-01T00:00:03Z] Running preflight installer
INFO[2024-01-01T00:00:03Z] Installing dependencies with package manager
INFO[2024-01-01T00:00:10Z] Installed dependencies with package manager
INFO[2024-01-01T00:00:10Z] Cleaning up preflight installer
INFO[2024-01-01T00:00:10Z] Completed preflight installer. Use 'longhornctl check preflight' to check the result.
```

--------------------------------

### Install Device Mapper Tool

Source: https://longhorn.io/docs/1.11.0/deploy/install

Commands to install the device mapper userspace tool for block device management.

```bash
apt-get install dmsetup
```

```bash
yum install device-mapper
```

```bash
zypper install device-mapper
```

--------------------------------

### Install open-iscsi on RHEL, CentOS, and EKS

Source: https://longhorn.io/docs/1.11.0/deploy/install

Install iscsi-initiator-utils and configure the initiator name on RHEL-based distributions and AmazonLinux2.

```bash
yum --setopt=tsflags=noscripts install iscsi-initiator-utils
echo "InitiatorName=$(/sbin/iscsi-iname)" > /etc/iscsi/initiatorname.iscsi
systemctl enable iscsid
systemctl start iscsid

```

--------------------------------

### Example values.yaml configuration

Source: https://longhorn.io/docs/1.11.0/advanced-resources/deploy/customizing-default-settings

A snippet showing how to define various default settings within the values.yaml file.

```yaml
defaultSettings:
  backupTarget: s3://backupbucket@us-east-1/backupstore
  backupTargetCredentialSecret: minio-secret
  createDefaultDiskLabeledNodes: true
  defaultDataPath: /var/lib/longhorn-example/
  replicaSoftAntiAffinity: false
  storageOverProvisioningPercentage: 600
  storageMinimalAvailablePercentage: 15
  upgradeChecker: false
  defaultReplicaCount: 2
  defaultDataLocality: disabled
  defaultLonghornStaticStorageClass: longhorn-static-example
  backupstorePollInterval: 500
  taintToleration: key1=value1:NoSchedule; key2:NoExecute
  systemManagedComponentsNodeSelector: "label-key1:label-value1"
  priorityClass: high-priority
  autoSalvage: false
  disableSchedulingOnCordonedNode: false
  replicaZoneSoftAntiAffinity: false
  replicaDiskSoftAntiAffinity: false
  volumeAttachmentRecoveryPolicy: never
  nodeDownPodDeletionPolicy: do-nothing
  guaranteedInstanceManagerCpu: 15
  orphanResourceAutoDeletion: ""
  orphanResourceAutoDeletionGracePeriod: 300
```

--------------------------------

### Install NFSv4 Client

Source: https://longhorn.io/docs/1.11.0/deploy/install

Commands to install the NFSv4 client utilities based on the Linux distribution.

```bash
apt-get install nfs-common
```

```bash
yum install nfs-utils
```

```bash
zypper install nfs-client
```

--------------------------------

### Simple Pod and PVC Configuration

Source: https://longhorn.io/docs/1.11.0/references/examples

Basic examples of a Pod and its associated PersistentVolumeClaim.

```yaml
    apiVersion: v1
    kind: Pod
    metadata:
      name: longhorn-simple-pod
      namespace: default
    spec:
      restartPolicy: Always
      containers:
        - name: volume-test
          image: nginx:stable-alpine
          imagePullPolicy: IfNotPresent
          livenessProbe:
            exec:
              command:
                - ls
                - /data/lost+found
            initialDelaySeconds: 5
            periodSeconds: 5
          volumeMounts:
            - name: volv
              mountPath: /data
          ports:
            - containerPort: 80
      volumes:
        - name: volv
          persistentVolumeClaim:
            claimName: longhorn-simple-pvc
```

```yaml
    apiVersion: v1
    kind: PersistentVolumeClaim
    metadata:
      name: longhorn-simple-pvc
    spec:
      accessModes:
        - ReadWriteOnce
      storageClassName: longhorn
      resources:
        requests:
          storage: 1Gi
```

--------------------------------

### View Kubernetes Version Output

Source: https://longhorn.io/docs/1.11.0/deploy/install

Example output showing client and server version information.

```text
Client Version: version.Info{Major:"1", Minor:"26", GitVersion:"v1.26.10", GitCommit:"b8609d4dd75c5d6fba4a5eaa63a5507cb39a6e99", GitTreeState:"clean", BuildDate:"2023-10-18T11:44:31Z", GoVersion:"go1.20.10", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"26", GitVersion:"v1.26.10+k3s2", GitCommit:"cb5cb5557f34e240e38c68a8c4ca2506c68b1d86", GitTreeState:"clean", BuildDate:"2023-11-08T03:21:46Z", GoVersion:"go1.20.10", Compiler:"gc", Platform:"linux/amd64"}
```

--------------------------------

### Verify installation

Source: https://longhorn.io/docs/1.11.0/advanced-resources/longhornctl/install-longhornctl

Checks that the longhornctl tool is correctly installed and accessible by printing its version.

```bash
longhornctl version
```

--------------------------------

### Install Fleet via Helm

Source: https://longhorn.io/docs/1.11.0/deploy/install/install-with-fleet

Commands to add the Fleet Helm repository and install the necessary CRDs and components.

```bash
helm repo add fleet https://rancher.github.io/fleet-helm-charts/
helm -n cattle-fleet-system install --create-namespace --wait fleet-crd fleet/fleet-crd
helm -n cattle-fleet-system install --create-namespace --wait fleet fleet/fleet
```

--------------------------------

### Verify Preflight Dependencies

Source: https://longhorn.io/docs/1.11.0/v2-data-engine/quick-start

Run the check command again after installation to verify that all environment settings are correct.

```bash
master:~# ./longhornctl check preflight --enable-spdk
INFO[2024-01-01T00:00:13Z] Initializing preflight checker
INFO[2024-01-01T00:00:13Z] Cleaning up preflight checker
INFO[2024-01-01T00:00:13Z] Running preflight checker
INFO[2024-01-01T00:00:16Z] Retrieved preflight checker result:
worker1:
  info:
  - Service iscsid is running
  - NFS4 is supported
  - Package nfs-common is installed
  - Package open-iscsi is installed
  - CPU instruction set sse4_2 is supported
  - HugePages is enabled
  - Module nvme_tcp is loaded
  - Module uio_pci_generic is loaded
```

--------------------------------

### Install binary to system path

Source: https://longhorn.io/docs/1.11.0/advanced-resources/longhornctl/install-longhornctl

Moves the validated binary to the /usr/local/bin directory for system-wide access.

```bash
sudo install longhornctl-linux-${ARCH} /usr/local/bin/longhornctl
```

--------------------------------

### Modified Deployment Manifest Example

Source: https://longhorn.io/docs/1.11.0/deploy/install/airgap

Full example of a deployment manifest updated for a private registry.

```yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: longhorn-ui
  name: longhorn-ui
  namespace: longhorn-system
spec:
  replicas: 1
  selector:
    matchLabels:
      app: longhorn-ui
  template:
    metadata:
      labels:
        app: longhorn-ui
    spec:
      containers:
      - name: longhorn-ui
        image: <REGISTRY_URL>/longhorn-ui:<LONGHORN_UI_IMAGE_TAG>   ## Add image name and tag here
        ports:
        - containerPort: 8000
        env:
          - name: LONGHORN_MANAGER_IP
            value: "http://longhorn-backend:9500"
      imagePullSecrets:
      - name: <SECRET_NAME>
      serviceAccountName: longhorn-service-account
```

--------------------------------

### Install Preflight Dependencies with Kubeconfig

Source: https://longhorn.io/docs/1.11.0/deploy/install

Installs preflight dependencies using a specific kubeconfig file and container image.

```bash
longhornctl --kubeconfig ~/.kube/config --image longhornio/longhorn-cli:v1.11.0 install preflight
```

--------------------------------

### Install Longhorn with HTTPRoute via Helm

Source: https://longhorn.io/docs/1.11.0/deploy/accessing-the-ui/longhorn-httproute

Enable HTTPRoute during Longhorn installation using Helm command-line flags.

```bash
helm install longhorn longhorn/longhorn \
  --namespace longhorn-system \
  --create-namespace \
  --set "httproute.enabled=true" \
  --set "httproute.parentRefs[0].name=my-gateway" \
  --set "httproute.parentRefs[0].namespace=default" \
  --set "httproute.hostnames[0]=longhorn.example.com"
```

--------------------------------

### Define a Backing Image Resource

Source: https://longhorn.io/docs/1.11.0/advanced-resources/backing-image/backing-image-backup

Example configuration for a BackingImage custom resource.

```yaml
apiVersion: longhorn.io/v1beta2
kind: BackingImage
metadata:
  name: parrot
  namespace: longhorn-system
spec:
  sourceType: download
  sourceParameters:
    url: https://longhorn-backing-image.s3-us-west-1.amazonaws.com/parrot.raw
  checksum: 304f3ed30ca6878e9056ee6f1b02b328239f0d0c2c1272840998212f9734b196371560b3b939037e4f4c2884ce457c2cbc9f0621f4f5d1ca983983c8cdf8cd9a
```

--------------------------------

### Create a Pod with Longhorn Volume

Source: https://longhorn.io/docs/1.11.0/nodes-and-volumes/volumes/create-volumes

Deploy a Pod and its associated PersistentVolumeClaim using the provided example manifest.

```bash
kubectl create -f https://raw.githubusercontent.com/longhorn/longhorn/v1.11.0/examples/pod_with_pvc.yaml
```

--------------------------------

### Install open-iscsi on Debian and Ubuntu

Source: https://longhorn.io/docs/1.11.0/deploy/install

Use the apt package manager to install open-iscsi on Debian or Ubuntu systems.

```bash
apt-get install open-iscsi

```

--------------------------------

### Example Block Device Output

Source: https://longhorn.io/docs/1.11.0/v2-data-engine/features/node-disk-support

Sample output showing block device mappings to PCI devices.

```text
lrwxrwxrwx  1 root root 0  Jul  30 12:20 loop0 -> ../devices/virtual/block/loop0
lrwxrwxrwx  1 root root 0 Feb 22 14:04 vda -> ../devices/pci0000:00/0000:00:02.3/0000:04:00.0/virtio2/block/vda
lrwxrwxrwx  1 root root 0 Feb 22 14:24 vdb -> ../devices/pci0000:00/0000:00:02.6/0000:07:00.0/virtio5/block/vdb
```

--------------------------------

### Install Longhorn via Helm

Source: https://longhorn.io/docs/1.11.0/deploy/install/airgap

Command to deploy Longhorn using the configured Helm chart.

```bash
helm install longhorn ./chart --namespace longhorn-system --create-namespace
```

--------------------------------

### Enable and start iSCSI daemon

Source: https://longhorn.io/docs/1.11.0/advanced-resources/os-distro-specific/csi-on-rke-and-coreos

Commands to manage the iSCSI daemon on the host system.

```bash
sudo su
systemctl enable iscsid
reboot
```

```bash
sudo su
systemctl start iscsid
```

--------------------------------

### Install Longhorn via Helm

Source: https://longhorn.io/docs/1.11.0/deploy/install/install-with-helm

Deploys Longhorn into the longhorn-system namespace using the specified version.

```bash
helm install longhorn longhorn/longhorn --namespace longhorn-system --create-namespace --version 1.11.0
```

--------------------------------

### Example output of successful cleanup

Source: https://longhorn.io/docs/1.11.0/deploy/uninstall

Shows the expected output after successfully deleting resources during the cleanup process.

```text
Warning: Detected changes to resource pvc-279e8c3e-bfb0-4233-8899-77b5b178c08c which is currently being deleted.
volumeattachment.longhorn.io/pvc-279e8c3e-bfb0-4233-8899-77b5b178c08c configured
No resources found
customresourcedefinition.apiextensions.k8s.io "volumeattachments.longhorn.io" deleted
```

--------------------------------

### Deploy Credentials and Service

Source: https://longhorn.io/docs/1.11.0/snapshots-and-backups/backup-and-restore/set-backup-target

Apply the generated Kustomize overlay to deploy the credentials.

```bash
kubectl apply -k deploy/backupstores/overlays/generated-credentials/azurite
```

--------------------------------

### Install Longhorn with custom values.yaml

Source: https://longhorn.io/docs/1.11.0/advanced-resources/deploy/customizing-default-settings

Apply the modified values.yaml file during the Helm installation.

```bash
helm install longhorn longhorn/longhorn \
  --namespace longhorn-system \
  --create-namespace \
  --values values.yaml
```

--------------------------------

### Deploy Credentials and Service

Source: https://longhorn.io/docs/1.11.0/snapshots-and-backups/backup-and-restore/set-backup-target

Apply the generated Kustomize overlay to the cluster.

```bash
kubectl apply -k deploy/backupstores/overlays/generated-credentials/minio
```

--------------------------------

### Apply and Verify Longhorn Installation

Source: https://longhorn.io/docs/1.11.0/deploy/install/install-with-fleet

Commands to apply the GitRepo resource and verify the status of the installation.

```bash
kubectl apply -f longhorn-gitrepo.yaml
```

```bash
kubectl -n fleet-local get gitrepo -w
```

```bash
kubectl -n longhorn-system get pod
```

--------------------------------

### View script help documentation

Source: https://longhorn.io/docs/1.11.0/deploy/install/airgap

Displays available command-line options for the image management scripts.

```bash
./save-images.sh --help
./load-images.sh --help
```

--------------------------------

### Install Linux Kernel Extra Modules

Source: https://longhorn.io/docs/1.11.0/v2-data-engine/quick-start

Install required kernel modules for Debian and Ubuntu systems.

```bash
apt install -y linux-modules-extra-`uname -r`
```

--------------------------------

### Generate Kustomize Overlay

Source: https://longhorn.io/docs/1.11.0/snapshots-and-backups/backup-and-restore/set-backup-target

Create the Kustomize overlay directory for the backupstore credentials.

```bash
./scripts/generate-backupstore-credentials.sh minio --no-encode
```

--------------------------------

### Deploy SMB/CIFS Credentials via Kustomize

Source: https://longhorn.io/docs/1.11.0/snapshots-and-backups/backup-and-restore/set-backup-target

Set environment variables and use the provided script to generate and deploy the Kustomize overlay for CIFS credentials.

```bash
export CIFS_USERNAME="example-cifs-username"
export CIFS_PASSWORD="example-cifs-password"
```

```bash
./scripts/generate-backupstore-credentials.sh cifs
```

```bash
kubectl apply -k deploy/backupstores/overlays/generated-credentials/cifs
```

--------------------------------

### Example Block Device Output

Source: https://longhorn.io/docs/1.11.0/v2-data-engine/features/node-disk-support

Sample output showing symbolic links for block devices and their PCI paths.

```text
lrwxrwxrwx  1 root root 0  Jul  30 12:20 loop0 -> ../devices/virtual/block/loop0
lrwxrwxrwx  1 root root 0  Jul  30 12:20 nvme0n1 -> ../devices/pci0000:00/0000:00:01.2/0000:02:00.0/nvme/nvme0/nvme0n1
lrwxrwxrwx  1 root root 0  Jul  30 12:20 nvme0n1 -> ../devices/pci0000:00/0000:00:01.2/0000:05:00.0/nvme/nvme1/nvme1n1
```

--------------------------------

### CSI Sidecar Operation Metrics Example

Source: https://longhorn.io/docs/1.11.0/monitoring/metrics

Example of histogram metrics for ControllerPublishVolume operations, showing bucketed latency and total operation counts.

```text
csi_sidecar_operations_seconds_bucket{driver_name="driver.longhorn.io",grpc_status_code="OK",method_name="/csi.v1.Controller/ControllerPublishVolume",le="0.1"} 0
csi_sidecar_operations_seconds_bucket{driver_name="driver.longhorn.io",grpc_status_code="OK",method_name="/csi.v1.Controller/ControllerPublishVolume",le="0.25"} 0
csi_sidecar_operations_seconds_bucket{driver_name="driver.longhorn.io",grpc_status_code="OK",method_name="/csi.v1.Controller/ControllerPublishVolume",le="0.5"} 0
csi_sidecar_operations_seconds_bucket{driver_name="driver.longhorn.io",grpc_status_code="OK",method_name="/csi.v1.Controller/ControllerPublishVolume",le="1"} 0
csi_sidecar_operations_seconds_bucket{driver_name="driver.longhorn.io",grpc_status_code="OK",method_name="/csi.v1.Controller/ControllerPublishVolume",le="2.5"} 3
csi_sidecar_operations_seconds_bucket{driver_name="driver.longhorn.io",grpc_status_code="OK",method_name="/csi.v1.Controller/ControllerPublishVolume",le="5"} 3
csi_sidecar_operations_seconds_bucket{driver_name="driver.longhorn.io",grpc_status_code="OK",method_name="/csi.v1.Controller/ControllerPublishVolume",le="10"} 3
csi_sidecar_operations_seconds_bucket{driver_name="driver.longhorn.io",grpc_status_code="OK",method_name="/csi.v1.Controller/ControllerPublishVolume",le="15"} 9
csi_sidecar_operations_seconds_bucket{driver_name="driver.longhorn.io",grpc_status_code="OK",method_name="/csi.v1.Controller/ControllerPublishVolume",le="25"} 9
csi_sidecar_operations_seconds_bucket{driver_name="driver.longhorn.io",grpc_status_code="OK",method_name="/csi.v1.Controller/ControllerPublishVolume",le="50"} 9
csi_sidecar_operations_seconds_bucket{driver_name="driver.longhorn.io",grpc_status_code="OK",method_name="/csi.v1.Controller/ControllerPublishVolume",le="120"} 9
csi_sidecar_operations_seconds_bucket{driver_name="driver.longhorn.io",grpc_status_code="OK",method_name="/csi.v1.Controller/ControllerPublishVolume",le="300"} 9
csi_sidecar_operations_seconds_bucket{driver_name="driver.longhorn.io",grpc_status_code="OK",method_name="/csi.v1.Controller/ControllerPublishVolume",le="600"} 9
csi_sidecar_operations_seconds_bucket{driver_name="driver.longhorn.io",grpc_status_code="OK",method_name="/csi.v1.Controller/ControllerPublishVolume",le="+Inf"} 9
csi_sidecar_operations_seconds_sum{driver_name="driver.longhorn.io",grpc_status_code="OK",method_name="/csi.v1.Controller/ControllerPublishVolume"} 66.816478825
csi_sidecar_operations_seconds_count{driver_name="driver.longhorn.io",grpc_status_code="OK",method_name="/csi.v1.Controller/ControllerPublishVolume"} 9
```

--------------------------------

### Example longhorn-manager warning logs

Source: https://longhorn.io/docs/1.11.0/advanced-resources/system-backup-restore/restore-to-a-new-cluster-using-velero

Sample logs indicating that old instance manager pods are present after restoration.

```text
[longhorn-manager-q6n7x] time="2021-12-20T10:42:49Z" level=warning msg="Can't find instance manager for pod instance-manager-r-1f19ecb0, may be deleted"
[longhorn-manager-q6n7x] time="2021-12-20T10:42:49Z" level=warning msg="Can't find instance manager for pod instance-manager-e-6c3be222, may be deleted"
[longhorn-manager-ldlvw] time="2021-12-20T10:42:55Z" level=warning msg="Can't find instance manager for pod instance-manager-e-bbf80f76, may be deleted"
[longhorn-manager-ldlvw] time="2021-12-20T10:42:55Z" level=warning msg="Can't find instance manager for pod instance-manager-r-3818fdca, may be deleted"
```

--------------------------------

### Install Longhorn

Source: https://longhorn.io/docs/1.11.0/deploy/install/install-with-kubectl

Apply the Longhorn manifest to your Kubernetes cluster.

```bash
kubectl apply -f https://raw.githubusercontent.com/longhorn/longhorn/v1.11.0/deploy/longhorn.yaml
```

--------------------------------

### Configure fleet.yaml Namespace

Source: https://longhorn.io/docs/1.11.0/deploy/install/install-with-fleet

Sets the default namespace for the Longhorn installation.

```yaml
defaultNamespace: longhorn-system
```

--------------------------------

### Create a loop block device

Source: https://longhorn.io/docs/1.11.0/v2-data-engine/quick-start

Creates a 10 GiB block device for testing purposes on a Longhorn node.

```bash
dd if=/dev/zero of=blockfile bs=1M count=10240
losetup -f blockfile
```

--------------------------------

### Configure ImagePullSecrets in Deployment

Source: https://longhorn.io/docs/1.11.0/deploy/install/airgap

Example of adding imagePullSecrets to a deployment manifest.

```yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: longhorn-ui
  name: longhorn-ui
  namespace: longhorn-system
spec:
  replicas: 1
  selector:
    matchLabels:
      app: longhorn-ui
  template:
    metadata:
      labels:
        app: longhorn-ui
    spec:
      containers:
      - name: longhorn-ui
        image: longhornio/longhorn-ui:v0.8.0
        ports:
        - containerPort: 8000
        env:
          - name: LONGHORN_MANAGER_IP
            value: "http://longhorn-backend:9500"
      imagePullSecrets:
      - name: <SECRET_NAME>                          ## Add SECRET_NAME here
      serviceAccountName: longhorn-service-account
```

--------------------------------

### Verify Longhorn Installation

Source: https://longhorn.io/docs/1.11.0/deploy/install/install-with-flux

Commands to check the status of the Helm release and the deployed pods.

```bash
flux get helmrelease longhorn-release -n longhorn-system
```

```bash
kubectl -n longhorn-system get pod
```

--------------------------------

### Apply Snapshot Manifest

Source: https://longhorn.io/docs/1.11.0/snapshots-and-backups/setup-a-snapshot

Use kubectl to apply the snapshot configuration file.

```bash
kubectl apply -f longhorn-snapshot.yaml
```

--------------------------------

### StorageClass Configuration Example

Source: https://longhorn.io/docs/1.11.0/nodes-and-volumes/volumes/create-volumes

A sample YAML definition for a Longhorn StorageClass, including parameters for replicas, filesystem type, and volume expansion.

```yaml
kind: StorageClass
apiVersion: storage.k8s.io/v1
metadata:
  name: longhorn
provisioner: driver.longhorn.io
allowVolumeExpansion: true
parameters:
  numberOfReplicas: "3"
  staleReplicaTimeout: "2880" # 48 hours in minutes
  fromBackup: ""
  fsType: "ext4"
#  backupTargetName: "default"
#  mkfsParams: "-I 256 -b 4096 -O ^metadata_csum,^64bit"
#  diskSelector: "ssd,fast"
#  nodeSelector: "storage,fast"
#  recurringJobSelector: '[
#   {
#     "name":"snap",
#     "isGroup":true,
#   },
#   {
#     "name":"backup",
#     "isGroup":false,
#   }
#  ]'
```

--------------------------------

### Example Replica Directory Path

Source: https://longhorn.io/docs/1.11.0/advanced-resources/data-recovery/corrupted-replica

The directory path where replica data is stored on a node.

```text
 /var/lib/longhorn/replicas/pvc-06b4a8a8-b51d-42c6-a8cc-d8c8d6bc65bc-d890efb2
```

--------------------------------

### Configure Persistent Huge Pages via GRUB

Source: https://longhorn.io/docs/1.11.0/v2-data-engine/quick-start

Add kernel boot parameters to /etc/default/grub to ensure huge page allocation persists after reboot.

```bash
GRUB_CMDLINE_LINUX="hugepagesz=2M hugepages=1024"
```

--------------------------------

### Troubleshoot System Restore Logs

Source: https://longhorn.io/docs/1.11.0/advanced-resources/system-backup-restore/restore-longhorn-system

Inspect the logs of the rollout pod to diagnose issues during a system restore.

```bash
> kubectl -n longhorn-system logs --selector=job-name=longhorn-system-rollout-<SYSTEM-RESTORE-NAME>
```

--------------------------------

### Troubleshooting and Information Retrieval

Source: https://longhorn.io/docs/1.11.0/advanced-resources/longhornctl

Commands to inspect replica status and get general help.

```bash
longhornctl get replica
```

```bash
longhornctl help
```

--------------------------------

### Longhorn Python Client Initialization

Source: https://longhorn.io/docs/1.11.0/references/longhorn-client-python

How to initialize the Longhorn client by providing the API endpoint URL.

```APIDOC
import longhorn

# Initialize client
client = longhorn.Client(url='http://localhost:8080/v1')
```

--------------------------------

### Apply GRUB Configuration

Source: https://longhorn.io/docs/1.11.0/v2-data-engine/quick-start

Commands to update the GRUB configuration based on the system architecture.

```bash
sudo update-grub
```

```bash
sudo grub2-mkconfig -o /boot/grub2/grub.cfg
```

```bash
sudo grub2-mkconfig -o /boot/efi/EFI/<distro>/grub.cfg
```

--------------------------------

### Rollback Longhorn via Kubectl

Source: https://longhorn.io/docs/1.11.0/deploy/upgrade/longhorn-manager

Revert to the previously installed version by applying its specific manifest.

```bash
kubectl apply -f https://raw.githubusercontent.com/longhorn/longhorn/[previous installed version]/deploy/longhorn.yaml
```
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