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docs: add usage guide for lvmo [skip ci]
Signed-off-by: Leela Venkaiah G <[email protected]>
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| ## Deploying LVMCluster CR | ||
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| This guide assumes you followed steps in [Readme][repo-readme] and LVM operator | ||
| (hereafter LVMO) is running in your cluster. | ||
|
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| Below are the available disks in our test kubernetes cluster node and there are | ||
| no existing LVM Physical Volumes, Volume Groups and Logical Volumes | ||
|
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| ``` console | ||
| sh-4.4# lsblk | ||
| NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT | ||
| sdb 8:16 0 893.8G 0 disk | ||
| |-sdb1 8:17 0 1M 0 part | ||
| |-sdb2 8:18 0 127M 0 part | ||
| |-sdb3 8:19 0 384M 0 part /boot | ||
| `-sdb4 8:20 0 893.3G 0 part /sysroot | ||
| sr0 11:0 1 987M 0 rom | ||
| nvme0n1 259:0 0 1.5T 0 disk | ||
| nvme1n1 259:1 0 1.5T 0 disk | ||
| nvme2n1 259:2 0 1.5T 0 disk | ||
| sh-4.4# pvs | ||
| sh-4.4# vgs | ||
| sh-4.4# lvs | ||
| ``` | ||
|
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| Here LVMO is installed in `lvm-operator-system` namespace via `make deploy` | ||
| target and operations will not change if LVMO is installed in any other namespaces. | ||
|
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| ``` console | ||
| kubectl get pods | ||
| NAME READY STATUS RESTARTS AGE | ||
| controller-manager-8bf864c85-8zjlp 3/3 Running 0 96s | ||
| ``` | ||
|
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| After all containers in above listing is in `READY` state we can proceed with | ||
| deploying LVMCluster CR | ||
|
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| ``` yaml | ||
| cat <<EOF | kubectl apply -f - | ||
| apiVersion: lvm.topolvm.io/v1alpha1 | ||
| kind: LVMCluster | ||
| metadata: | ||
| name: lvmcluster-sample | ||
| # set the namespace to the operator namespace | ||
| namespace: lvm-operator-system | ||
| spec: | ||
| deviceClasses: | ||
| - name: vg1 | ||
| EOF | ||
| ``` | ||
|
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||
| - Ability to respect Node Selector, Tolerations and Device Selectors in above CR | ||
| is coming soon. | ||
| - After deploying above CR all free disks will be used to create a volume | ||
| group, topolvm csi is deployed and all the corresponding resources are | ||
| created, including storage class for ready consumption of Persistent Volumes | ||
| based on Topolvm | ||
|
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| - Wait for all the pods to be in `READY` state | ||
| - `topolvm-controller` and `topolvm-node` will be in `init` stage for a while | ||
| awaiting creation of certs and creation of volume groups by `vg-manager` | ||
| respectively | ||
|
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||
| ``` console | ||
| kubectl get pods | ||
| NAME READY STATUS RESTARTS AGE | ||
| controller-manager-8bf864c85-8zjlp 3/3 Running 0 31m | ||
| topolvm-controller-694bc98b87-x6dxn 4/4 Running 0 10m | ||
| topolvm-node-pbcth 4/4 Running 0 10m | ||
| vg-manager-f979f 1/1 Running 0 10m | ||
| ``` | ||
| When all pods are ready, the LVM physical volumes and volume groups should be | ||
| created on the host. | ||
|
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||
| ``` console | ||
| sh-4.4# pvs | ||
| PV VG Fmt Attr PSize PFree | ||
| /dev/nvme0n1 vg1 lvm2 a-- <1.46t <1.46t | ||
| /dev/nvme1n1 vg1 lvm2 a-- <1.46t <1.46t | ||
| /dev/nvme2n1 vg1 lvm2 a-- <1.46t <1.46t | ||
| sh-4.4# vgs | ||
| VG #PV #LV #SN Attr VSize VFree | ||
| vg1 3 0 0 wz--n- <4.37t <4.37t | ||
| ``` | ||
|
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| Confirm that the following resources have been created on the cluster: | ||
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| - When LVMCluster CR is deployed which contains details of all volume groups that | ||
| needs to be created across multiple nodes, two supporting Custom Resources | ||
| are created by LVMO | ||
| - LVMVolumeGroup: CR created and managed by LVMO which tracks individual volume | ||
| groups across multiple nodes | ||
| ``` yaml | ||
| # kubectl get lvmvolumegroup vg1 -oyaml | ||
| apiVersion: lvm.topolvm.io/v1alpha1 | ||
| kind: LVMVolumeGroup | ||
| metadata: | ||
| creationTimestamp: "2022-02-02T05:16:42Z" | ||
| generation: 1 | ||
| name: vg1 | ||
| namespace: lvm-operator-system | ||
| resourceVersion: "17242461" | ||
| uid: 88e8ad7d-1544-41fb-9a8e-12b1a66ab157 | ||
| spec: {} | ||
| ``` | ||
| - LVMVolumeGroupNodeStatus: CR created and managed by VG Manager which tracks | ||
| node status corresponding to multiple volume groups | ||
| ``` yaml | ||
| # kubectl get lvmvolumegroupnodestatuses.lvm.topolvm.io kube-node -oyaml | ||
| apiVersion: lvm.topolvm.io/v1alpha1 | ||
| kind: LVMVolumeGroupNodeStatus | ||
| metadata: | ||
| creationTimestamp: "2022-02-02T05:17:59Z" | ||
| generation: 1 | ||
| name: kube-node | ||
| namespace: lvm-operator-system | ||
| resourceVersion: "17242882" | ||
| uid: 292de9bb-3a9b-4ee8-946a-9b587986dafd | ||
| spec: | ||
| nodeStatus: | ||
| - devices: | ||
| - /dev/nvme0n1 | ||
| - /dev/nvme1n1 | ||
| - /dev/nvme2n1 | ||
| name: vg1 | ||
| status: Ready | ||
| ``` | ||
| - A storage class called `topolvm-<deviceclassname>` will be created | ||
| ``` console | ||
| # kubectl get storageclass | ||
| NAME PROVISIONER RECLAIMPOLICY VOLUMEBINDINGMODE ALLOWVOLUMEEXPANSION AGE | ||
| topolvm-vg1 topolvm.cybozu.com Delete WaitForFirstConsumer true 31m | ||
| ``` | ||
|
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| Note: | ||
| - Reconciling multiple LVMCluster CRs by LVMO is not supported | ||
| - Custom resources LVMVolumeGroup and LVMVolumeGroupNodeStatus are managed by | ||
| LVMO and users should not edit them. | ||
|
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| ## Deploying PVC and App Pod | ||
|
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| - A successful reconciliation of LVMCluster CR will setup all the underlying | ||
| resources needed to be able to create a PVC and use it in app pod, the same | ||
| can be verified from LVMCluster CR status field | ||
| ```json | ||
| # kubectl get lvmclusters.lvm.topolvm.io -ojsonpath='{.items[*].status.deviceClassStatuses[*]}' | python3 -mjson.tool | ||
| { | ||
| "name": "vg1", | ||
| "nodeStatus": [ | ||
| { | ||
| "devices": [ | ||
| "/dev/nvme0n1", | ||
| "/dev/nvme1n1", | ||
| "/dev/nvme2n1" | ||
| ], | ||
| "node": "kube-node", | ||
| "status": "Ready" | ||
| } | ||
| ] | ||
| } | ||
| ``` | ||
| - Create a PVC using the StorageClass created for the deviceClass. The PVC will | ||
| not be bound until a pod claims the storage as the volume binding mode is set | ||
| to WaitForFirstConsumer. | ||
| ```yaml | ||
| cat <<EOF | kubectl apply -f - | ||
| apiVersion: v1 | ||
| kind: PersistentVolumeClaim | ||
| metadata: | ||
| name: lvm-file-pvc | ||
| spec: | ||
| volumeMode: Filesystem | ||
| accessModes: | ||
| - ReadWriteOnce | ||
| resources: | ||
| requests: | ||
| storage: 5Gi | ||
| storageClassName: topolvm-vg1 | ||
| EOF | ||
| ``` | ||
| ``` console | ||
| kubectl get pvc | ||
| NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE | ||
| lvm-file-pvc Pending topolvm-vg1 12s | ||
| ``` | ||
| - In a multi node setup the `WaitForFirstConsumer` volume binding is used to | ||
| take scheduling decisions of pod placement which usually prefers the node | ||
| having highest amount of available storage space | ||
| - Deploy an app pod that uses the PVC created earlier. | ||
| ``` yaml | ||
| cat <<EOF | kubectl apply -f - | ||
| apiVersion: v1 | ||
| kind: Pod | ||
| metadata: | ||
| name: app-file | ||
| spec: | ||
| containers: | ||
| - name: app-file | ||
| image: bash | ||
| imagePullPolicy: IfNotPresent | ||
| command: ["/usr/local/bin/bash", "-c", "/usr/bin/tail -f /dev/null"] | ||
| volumeMounts: | ||
| - mountPath: "/mnt/file" | ||
| name: lvm-file-pvc | ||
| volumes: | ||
| - name: lvm-file-pvc | ||
| persistentVolumeClaim: | ||
| claimName: lvm-file-pvc | ||
| EOF | ||
| ``` | ||
| - App pod should claim the PVC and be in `READY`, PVC will get bound to this | ||
| app | ||
| ``` console | ||
| kubectl get pod | grep -E '^(app|NAME)' | ||
| NAME READY STATUS RESTARTS AGE | ||
| app-file 1/1 Running 0 2m6s | ||
| kubectl get pvc | ||
| NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE | ||
| lvm-file-pvc Bound pvc-04a4f5f7-8665-4008-818a-490503c859f5 5Gi RWO topolvm-vg1 5m55s | ||
| ``` | ||
| - To create a PVC with `volumeMode: Block`, do the following: | ||
| ``` yaml | ||
| cat <<EOF | kubectl apply -f - | ||
| --- | ||
| apiVersion: v1 | ||
| kind: PersistentVolumeClaim | ||
| metadata: | ||
| name: lvm-block-pvc | ||
| spec: | ||
| volumeMode: Block | ||
| accessModes: | ||
| - ReadWriteOnce | ||
| resources: | ||
| requests: | ||
| storage: 5Gi | ||
| storageClassName: topolvm-vg1 | ||
| --- | ||
| apiVersion: v1 | ||
| kind: Pod | ||
| metadata: | ||
| name: app-block | ||
| spec: | ||
| containers: | ||
| - name: app-block | ||
| image: bash | ||
| imagePullPolicy: IfNotPresent | ||
| command: ["/usr/local/bin/bash", "-c", "/usr/bin/tail -f /dev/null"] | ||
| volumeDevices: | ||
| - devicePath: "/dev/xvda" | ||
| name: lvm-block-pvc | ||
| volumes: | ||
| - name: lvm-block-pvc | ||
| persistentVolumeClaim: | ||
| claimName: lvm-block-pvc | ||
| EOF | ||
| ``` | ||
| - Check the status of both PVCs and App pods: | ||
| ``` console | ||
| kubectl get pod | grep -E '^(app|NAME)' | ||
| NAME READY STATUS RESTARTS AGE | ||
| app-block 1/1 Running 0 99s | ||
| app-file 1/1 Running 0 9m34s | ||
| kubectl get pvc | ||
| NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE | ||
| lvm-block-pvc Bound pvc-56fe959a-1184-4fa6-9d66-b69c06d43cf4 5Gi RWO topolvm-vg1 104s | ||
| lvm-file-pvc Bound pvc-04a4f5f7-8665-4008-818a-490503c859f5 5Gi RWO topolvm-vg1 13m | ||
| ``` | ||
|
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| ### Monitoring and Metrics | ||
|
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| - LVMO currently surfaces only Topolvm metrics and those can be viewed either | ||
| from UI or port-forwarding the service | ||
| - On Openshift clusters, set the label "openshift.io/cluster-monitoring" on the | ||
| namespace the LVMO is running in. | ||
| ``` console | ||
| kubectl patch namespace/lvm-operator-system -p '{"metadata": {"labels": {"openshift.io/cluster-monitoring": "true"}}}' | ||
| ``` | ||
| ``` console | ||
| # port-forward service in one terminal | ||
| kubectl port-forward svc/topolvm-node-metrics :8080 | ||
| Forwarding from 127.0.0.1:41685 -> 8080 | ||
| Forwarding from [::1]:41685 -> 8080 | ||
| ... | ||
| ... | ||
| # in another terminal view the metrics at above port in localhost | ||
| curl -s 127.0.0.1:41685/metrics | grep -Ei 'topolvm_volumegroup_.*?_bytes\{' | ||
| topolvm_volumegroup_available_bytes{device_class="vg1",node="kube-node"} 4.790222323712e+12 | ||
| topolvm_volumegroup_size_bytes{device_class="vg1",node="kube-node"} 4.800959741952e+12 | ||
| ``` | ||
|
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| ## Cleanup | ||
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| - Feature to auto cleanup volume groups after removing LVMCluster CR is coming | ||
| soon | ||
| - Until then, please perform the following steps to cleanup the resources | ||
| created by the operator | ||
|
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| ### Steps | ||
|
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| 1. Remove all the apps which are using PVCs created with topolvm | ||
| ``` console | ||
| # delete App pod first | ||
| kubectl delete pod app-file app-block | ||
| pod "app-file" deleted | ||
| pod "app-block" deleted | ||
| # delete PVCs which were used by above App pods | ||
| kubectl delete pvc lvm-file-pvc lvm-block-pvc | ||
| persistentvolumeclaim "lvm-file-pvc" deleted | ||
| persistentvolumeclaim "lvm-block-pvc" deleted | ||
| ``` | ||
| 2. Make sure there are no `logicalvolumes` CRs which were created by topolvm | ||
| ``` console | ||
| kubectl get logicalvolumes.topolvm.cybozu.com | ||
| No resources found | ||
| ``` | ||
| 3. Take a json dump of LVMCluster CR contents. It has the list of VGs and PVs | ||
| created on the nodes. | ||
| ``` console | ||
| kubectl get lvmclusters.lvm.topolvm.io -ojson > /tmp/lvmcr.json | ||
| ``` | ||
| 4. Either parse contents from above json file via jq or store status of the CR | ||
| ``` console | ||
| kubectl get lvmclusters.lvm.topolvm.io -ojsonpath='{.items[*].status.deviceClassStatuses[*]}' | python3 -mjson.tool | ||
| ``` | ||
| ``` json | ||
| { | ||
| "name": "vg1", | ||
| "nodeStatus": [ | ||
| { | ||
| "devices": [ | ||
| "/dev/nvme0n1", | ||
| "/dev/nvme1n1", | ||
| "/dev/nvme2n1" | ||
| ], | ||
| "node": "kube-node", | ||
| "status": "Ready" | ||
| } | ||
| ] | ||
| } | ||
| ``` | ||
| 5. Remove LVMCluster CR and wait for deletion of all resources in the namespace | ||
| except the operator (controller-manager pod) | ||
| ``` console | ||
| kubectl delete lvmclusters.lvm.topolvm.io lvmcluster-sample | ||
| lvmcluster.lvm.topolvm.io "lvmcluster-sample" deleted | ||
| kubectl get po | ||
| NAME READY STATUS RESTARTS AGE | ||
| controller-manager-8bf864c85-8zjlp 3/3 Running 0 125m | ||
| ``` | ||
| 6. Login to the node and remove the LVM volume groups and physical volumes | ||
| ``` console | ||
| sh-4.4# vgremove vg1 --nolock | ||
| WARNING: File locking is disabled. | ||
| Volume group "vg1" successfully removed | ||
| sh-4.4# pvremove /dev/nvme0n1 /dev/nvme1n1 /dev/nvme2n1 --nolock | ||
| WARNING: File locking is disabled. | ||
| Labels on physical volume "/dev/nvme0n1" successfully wiped. | ||
| Labels on physical volume "/dev/nvme1n1" successfully wiped. | ||
| Labels on physical volume "/dev/nvme2n1" successfully wiped. | ||
| ``` | ||
| 7. Remove the lvmd.yaml config file from the node | ||
| ``` console | ||
| sh-4.4# rm /etc/topolvm/lvmd.yaml | ||
| ``` | ||
| Note: | ||
| - Removal of volume groups, physical volumes and lvm config file is necessary | ||
| during cleanup or else LVMO fails to deploy Topolvm in next iteration. | ||
|
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| ## Uninstalling LVMO | ||
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| - LVMO can be removed from the cluster via one of the following methods based | ||
| on your installation | ||
| ``` console | ||
| # if deployed via manifests | ||
| make undeploy | ||
| # if deployed via olm | ||
| make undeploy-with-olm | ||
| ``` | ||
|
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| [repo-readme]: ../../README.md |