-
Theoretical size.
-
Tested size.
Logical volume manager storage (LVM Storage) uses the TopoLVM CSI driver to dynamically provision local storage on single-node OpenShift clusters.
LVM Storage creates thin-provisioned volumes using Logical Volume Manager and provides dynamic provisioning of block storage on a limited resources single-node OpenShift cluster.
You can deploy LVM Storage on a single-node OpenShift bare-metal or user-provisioned infrastructure cluster and configure it to dynamically provision storage for your workloads.
LVM Storage creates a volume group using all the available unused disks and creates a single thin pool with a size of 90% of the volume group. The remaining 10% of the volume group is left free to enable data recovery by expanding the thin pool when required. You might need to manually perform such recovery.
You can use persistent volume claims (PVCs) and volume snapshots provisioned by LVM Storage to request storage and create volume snapshots.
LVM Storage configures a default overprovisioning limit of 10 to take advantage of the thin-provisioning feature. The total size of the volumes and volume snapshots that can be created on the single-node OpenShift clusters is 10 times the size of the thin pool.
You can deploy LVM Storage on single-node OpenShift clusters using one of the following:
Red Hat Advanced Cluster Management (RHACM)
OKD Web Console
Before you begin deploying LVM Storage on single-node OpenShift clusters, ensure that the following requirements are met:
You have installed Red Hat Advanced Cluster Management (RHACM) on an OKD cluster.
Every managed single-node OpenShift cluster has dedicated disks that are used to provision storage.
Before you deploy LVM Storage on single-node OpenShift clusters, be aware of the following limitations:
You can only create a single instance of the LVMCluster
custom resource (CR) on an OKD cluster.
When a device becomes part of the LVMCluster
CR, it cannot be removed.
For deploying single-node OpenShift, LVM Storage has the following limitations:
The total storage size is limited by the size of the underlying Logical Volume Manager (LVM) thin pool and the overprovisioning factor.
The size of the logical volume depends on the size of the Physical Extent (PE) and the Logical Extent (LE).
It is possible to define the size of PE and LE during the physical and logical device creation.
The default PE and LE size is 4 MB.
If the size of the PE is increased, the maximum size of the LVM is determined by the kernel limits and your disk space.
Architecture | RHEL 5 | RHEL 6 | RHEL 7 | RHEL 8 |
---|---|---|---|---|
32-bit |
16 TB |
16 TB |
- |
- |
64-bit |
8 EB [1] |
8 EB [1] 100 TB [2] |
8 EB [1] 500 TB [2] |
8 EB |
Theoretical size.
Tested size.
As a cluster administrator, you can install Logical volume manager storage (LVM Storage) by using the CLI.
You have installed the OpenShift CLI (oc
).
You have logged in as a user with cluster-admin
privileges.
Create a namespace for the LVM Storage Operator.
Save the following YAML in the lvms-namespace.yaml
file:
apiVersion: v1
kind: Namespace
metadata:
labels:
openshift.io/cluster-monitoring: "true"
pod-security.kubernetes.io/enforce: privileged
pod-security.kubernetes.io/audit: privileged
pod-security.kubernetes.io/warn: privileged
name: openshift-storage
Create the Namespace
CR:
$ oc create -f lvms-namespace.yaml
Create an Operator group for the LVM Storage Operator.
Save the following YAML in the lvms-operatorgroup.yaml
file:
apiVersion: operators.coreos.com/v1
kind: OperatorGroup
metadata:
name: openshift-storage-operatorgroup
namespace: openshift-storage
spec:
targetNamespaces:
- openshift-storage
Create the OperatorGroup
CR:
$ oc create -f lvms-operatorgroup.yaml
Subscribe to the LVM Storage Operator.
Save the following YAML in the lvms-sub.yaml
file:
apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
name: lvms
namespace: openshift-storage
spec:
installPlanApproval: Automatic
name: lvms-operator
source: redhat-operators
sourceNamespace: openshift-marketplace
Create the Subscription
CR:
$ oc create -f lvms-sub.yaml
Create the LVMCluster
resource:
Save the following YAML in the lvmcluster.yaml
file:
apiVersion: lvm.topolvm.io/v1alpha1
kind: LVMCluster
metadata:
name: my-lvmcluster
namespace: openshift-storage
spec:
storage:
deviceClasses:
- name: vg1
deviceSelector:
paths:
- /dev/disk/by-path/pci-0000:87:00.0-nvme-1
- /dev/disk/by-path/pci-0000:88:00.0-nvme-1
optionalPaths:
- /dev/disk/by-path/pci-0000:89:00.0-nvme-1
- /dev/disk/by-path/pci-0000:90:00.0-nvme-1
thinPoolConfig:
name: thin-pool-1
sizePercent: 90
overprovisionRatio: 10
nodeSelector:
nodeSelectorTerms:
- matchExpressions:
- key: app
operator: In
values:
- test1
Create the LVMCluster
CR:
$ oc create -f lvmcluster.yaml
To verify that the Operator is installed, enter the following command:
$ oc get csv -n openshift-storage -o custom-columns=Name:.metadata.name,Phase:.status.phase
Name Phase
4.13.0-202301261535 Succeeded
You can install Logical volume manager storage (LVM Storage) by using the Red Hat OKD OperatorHub.
You have access to the single-node OpenShift cluster.
You are using an account with the cluster-admin
and Operator installation permissions.
Log in to the OKD Web Console.
Click Operators → OperatorHub.
Scroll or type LVM Storage
into the Filter by keyword box to find LVM Storage.
Click Install.
Set the following options on the Install Operator page:
Update Channel as stable-4.
Installation Mode as A specific namespace on the cluster.
Installed Namespace as Operator recommended namespace openshift-storage.
If the openshift-storage
namespace does not exist, it is created during the operator installation.
Approval Strategy as Automatic or Manual.
If you select Automatic updates, then the Operator Lifecycle Manager (OLM) automatically upgrades the running instance of your Operator without any intervention.
If you select Manual updates, then the OLM creates an update request. As a cluster administrator, you must then manually approve that update request to update the Operator to a newer version.
Click Install.
Verify that LVM Storage shows a green tick, indicating successful installation.
You can unstall LVM Storage using the Red Hat OpenShift Container Platform Web Console.
You deleted all the applications on the clusters that are using the storage provisioned by LVM Storage.
You deleted the persistent volume claims (PVCs) and persistent volumes (PVs) provisioned using LVM Storage.
You deleted all volume snapshots provisioned by LVM Storage.
You verified that no logical volume resources exist by using the oc get logicalvolume
command.
You have access to the single-node OpenShift cluster using an account with cluster-admin
permissions.
From the Operators → Installed Operators page, scroll to LVM Storage or type LVM Storage
into the Filter by name to find and click on it.
Click on the LVMCluster tab.
On the right-hand side of the LVMCluster page, select Delete LVMCluster from the Actions drop-down menu.
Click on the Details tab.
On the right-hand side of the Operator Details page, select Uninstall Operator from the Actions drop-down menu.
Select Remove. LVM Storage stops running and is completely removed.
You can install LVM Storage on OKD 4 in a disconnected environment. All sections referenced in this procedure are linked in Additional resources.
You read the About disconnected installation mirroring section.
You have access to the OKD image repository.
You created a mirror registry.
Follow the steps in the Creating the image set configuration procedure. To create an ImageSetConfiguration
resource for LVM Storage, you can use the following example YAML file:
kind: ImageSetConfiguration
apiVersion: mirror.openshift.io/v1alpha2
archiveSize: 4 (1)
storageConfig: (2)
registry:
imageURL: example.com/mirror/oc-mirror-metadata (3)
skipTLS: false
mirror:
platform:
channels:
- name: stable-4 (4)
type: ocp
graph: true (5)
operators:
- catalog: registry.redhat.io/redhat/redhat-operator-index:v4 (6)
packages:
- name: lvms-operator (7)
channels:
- name: stable (8)
additionalImages:
- name: registry.redhat.io/ubi9/ubi:latest (9)
helm: {}
1 | Add archiveSize to set the maximum size, in GiB, of each file within the image set. |
2 | Set the back-end location to save the image set metadata to. This location can be a registry or local directory. It is required to specify storageConfig values, unless you are using the Technology Preview OCI feature. |
3 | Set the registry URL for the storage backend. |
4 | Set the channel to retrieve the OKD images from. |
5 | Add graph: true to generate the OpenShift Update Service (OSUS) graph image to allow for an improved cluster update experience when using the web console. For more information, see About the OpenShift Update Service. |
6 | Set the Operator catalog to retrieve the OKD images from. |
7 | Specify only certain Operator packages to include in the image set. Remove this field to retrieve all packages in the catalog. |
8 | Specify only certain channels of the Operator packages to include in the image set. You must always include the default channel for the Operator package even if you do not use the bundles in that channel. You can find the default channel by running the following command: oc mirror list operators --catalog=<catalog_name> --package=<package_name> . |
9 | Specify any additional images to include in image set. |
Follow the procedure in the Mirroring an image set to a mirror registry section.
Follow the procedure in the Configuring image registry repository mirroring section.
LVM Storage is deployed on single-node OpenShift clusters using Red Hat Advanced Cluster Management (RHACM).
You create a Policy
object on RHACM that deploys and configures the Operator when it is applied to managed clusters which match the selector specified in the PlacementRule
resource.
The policy is also applied to clusters that are imported later and satisfy the placement rule.
Access to the RHACM cluster using an account with cluster-admin
and Operator installation permissions.
Dedicated disks on each single-node OpenShift cluster to be used by LVM Storage.
The single-node OpenShift cluster needs to be managed by RHACM, either imported or created.
Log in to the RHACM CLI using your OKD credentials.
Create a namespace in which you will create policies.
# oc create ns lvms-policy-ns
To create a policy, save the following YAML to a file with a name such as policy-lvms-operator.yaml
:
apiVersion: apps.open-cluster-management.io/v1
kind: PlacementRule
metadata:
name: placement-install-lvms
spec:
clusterConditions:
- status: "True"
type: ManagedClusterConditionAvailable
clusterSelector: (1)
matchExpressions:
- key: mykey
operator: In
values:
- myvalue
---
apiVersion: policy.open-cluster-management.io/v1
kind: PlacementBinding
metadata:
name: binding-install-lvms
placementRef:
apiGroup: apps.open-cluster-management.io
kind: PlacementRule
name: placement-install-lvms
subjects:
- apiGroup: policy.open-cluster-management.io
kind: Policy
name: install-lvms
---
apiVersion: policy.open-cluster-management.io/v1
kind: Policy
metadata:
annotations:
policy.open-cluster-management.io/categories: CM Configuration Management
policy.open-cluster-management.io/controls: CM-2 Baseline Configuration
policy.open-cluster-management.io/standards: NIST SP 800-53
name: install-lvms
spec:
disabled: false
remediationAction: enforce
policy-templates:
- objectDefinition:
apiVersion: policy.open-cluster-management.io/v1
kind: ConfigurationPolicy
metadata:
name: install-lvms
spec:
object-templates:
- complianceType: musthave
objectDefinition:
apiVersion: v1
kind: Namespace
metadata:
labels:
openshift.io/cluster-monitoring: "true"
pod-security.kubernetes.io/enforce: privileged
pod-security.kubernetes.io/audit: privileged
pod-security.kubernetes.io/warn: privileged
name: openshift-storage
- complianceType: musthave
objectDefinition:
apiVersion: operators.coreos.com/v1
kind: OperatorGroup
metadata:
name: openshift-storage-operatorgroup
namespace: openshift-storage
spec:
targetNamespaces:
- openshift-storage
- complianceType: musthave
objectDefinition:
apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
name: lvms
namespace: openshift-storage
spec:
installPlanApproval: Automatic
name: lvms-operator
source: redhat-operators
sourceNamespace: openshift-marketplace
remediationAction: enforce
severity: low
- objectDefinition:
apiVersion: policy.open-cluster-management.io/v1
kind: ConfigurationPolicy
metadata:
name: lvms
spec:
object-templates:
- complianceType: musthave
objectDefinition:
apiVersion: lvm.topolvm.io/v1alpha1
kind: LVMCluster
metadata:
name: my-lvmcluster
namespace: openshift-storage
spec:
storage:
deviceClasses:
- name: vg1
default: true
deviceSelector: (2)
paths:
- /dev/disk/by-path/pci-0000:87:00.0-nvme-1
- /dev/disk/by-path/pci-0000:88:00.0-nvme-1
optionalPaths:
- /dev/disk/by-path/pci-0000:89:00.0-nvme-1
- /dev/disk/by-path/pci-0000:90:00.0-nvme-1
thinPoolConfig:
name: thin-pool-1
sizePercent: 90
overprovisionRatio: 10
nodeSelector: (3)
nodeSelectorTerms:
- matchExpressions:
- key: app
operator: In
values:
- test1
remediationAction: enforce
severity: low
1 | Replace the key and value in PlacementRule.spec.clusterSelector to match the labels set on the single-node OpenShift clusters on which you want to install LVM Storage. |
2 | Optional. To control or restrict the volume group to your preferred devices, you can manually specify the local paths of the devices in the deviceSelector section of the LVMCluster YAML. The paths section refers to devices the LVMCluster adds, which means those paths must exist. The optionalPaths section refers to devices the LVMCluster might add. You must specify at least one of paths or optionalPaths when specifying the deviceSelector section. If you specify paths , it is not mandatory to specify optionalPaths . If you specify optionalPaths , it is not mandatory to specify paths but at least one optional path must be present on the node. If you do not specify any paths, it will add all unused devices on the node. |
3 | To add a node filter, which is a subset of the additional worker nodes, specify the required filter in the nodeSelector section. LVM Storage detects and uses the additional worker nodes when the new nodes show up. |
This |
Create the policy in the namespace by running the following command:
# oc create -f policy-lvms-operator.yaml -n lvms-policy-ns (1)
1 | The policy-lvms-operator.yaml is the name of the file to which the policy is saved. |
This creates a Policy
, a PlacementRule
, and a PlacementBinding
object in the lvms-policy-ns
namespace.
The policy creates a Namespace
, OperatorGroup
, Subscription
, and LVMCluster
resource on the clusters that match the placement rule.
This deploys the Operator on the single-node OpenShift clusters which match the selection criteria and configures it to set up the required resources to provision storage.
The Operator uses all the disks specified in the LVMCluster
CR.
If no disks are specified, the Operator uses all the unused disks on the single-node OpenShift node.
After a device is added to the |
To uninstall LVM Storage that you installed using RHACM, you need to delete the RHACM policy that you created for deploying and configuring the Operator.
When you delete the RHACM policy, the resources that the policy has created are not removed. You need to create additional policies to remove the resources.
As the created resources are not removed when you delete the policy, you need to perform the following steps:
Remove all the Persistent volume claims (PVCs) and volume snapshots provisioned by LVM Storage.
Remove the LVMCluster
resources to clean up Logical Volume Manager resources created on the disks.
Create an additional policy to uninstall the Operator.
Ensure that the following are deleted before deleting the policy:
All the applications on the managed clusters that are using the storage provisioned by LVM Storage.
PVCs and persistent volumes (PVs) provisioned using LVM Storage.
All volume snapshots provisioned by LVM Storage.
Ensure you have access to the RHACM cluster using an account with a cluster-admin
role.
In the OpenShift CLI (oc
), delete the RHACM policy that you created for deploying and configuring LVM Storage on the hub cluster by using the following command:
# oc delete -f policy-lvms-operator.yaml -n lvms-policy-ns (1)
1 | The policy-lvms-operator.yaml is the name of the file to which the policy was saved. |
To create a policy for removing the LVMCluster
resource, save the following YAML to a file with a name such as lvms-remove-policy.yaml
.
This enables the Operator to clean up all Logical Volume Manager resources that it created on the cluster.
apiVersion: policy.open-cluster-management.io/v1
kind: Policy
metadata:
name: policy-lvmcluster-delete
annotations:
policy.open-cluster-management.io/standards: NIST SP 800-53
policy.open-cluster-management.io/categories: CM Configuration Management
policy.open-cluster-management.io/controls: CM-2 Baseline Configuration
spec:
remediationAction: enforce
disabled: false
policy-templates:
- objectDefinition:
apiVersion: policy.open-cluster-management.io/v1
kind: ConfigurationPolicy
metadata:
name: policy-lvmcluster-removal
spec:
remediationAction: enforce (1)
severity: low
object-templates:
- complianceType: mustnothave
objectDefinition:
kind: LVMCluster
apiVersion: lvm.topolvm.io/v1alpha1
metadata:
name: my-lvmcluster
namespace: openshift-storage (2)
---
apiVersion: policy.open-cluster-management.io/v1
kind: PlacementBinding
metadata:
name: binding-policy-lvmcluster-delete
placementRef:
apiGroup: apps.open-cluster-management.io
kind: PlacementRule
name: placement-policy-lvmcluster-delete
subjects:
- apiGroup: policy.open-cluster-management.io
kind: Policy
name: policy-lvmcluster-delete
---
apiVersion: apps.open-cluster-management.io/v1
kind: PlacementRule
metadata:
name: placement-policy-lvmcluster-delete
spec:
clusterConditions:
- status: "True"
type: ManagedClusterConditionAvailable
clusterSelector:
matchExpressions:
- key: mykey
operator: In
values:
- myvalue
1 | The policy-template spec.remediationAction is overridden by the preceding parameter value for spec.remediationAction . |
2 | This namespace field must have the openshift-storage value. |
Set the value of the PlacementRule.spec.clusterSelector
field to select the clusters from which to uninstall LVM Storage.
Create the policy by running the following command:
# oc create -f lvms-remove-policy.yaml -n lvms-policy-ns
To create a policy to check if the LVMCluster
CR has been removed, save the following YAML to a file with a name such as check-lvms-remove-policy.yaml
:
apiVersion: policy.open-cluster-management.io/v1
kind: Policy
metadata:
name: policy-lvmcluster-inform
annotations:
policy.open-cluster-management.io/standards: NIST SP 800-53
policy.open-cluster-management.io/categories: CM Configuration Management
policy.open-cluster-management.io/controls: CM-2 Baseline Configuration
spec:
remediationAction: inform
disabled: false
policy-templates:
- objectDefinition:
apiVersion: policy.open-cluster-management.io/v1
kind: ConfigurationPolicy
metadata:
name: policy-lvmcluster-removal-inform
spec:
remediationAction: inform (1)
severity: low
object-templates:
- complianceType: mustnothave
objectDefinition:
kind: LVMCluster
apiVersion: lvm.topolvm.io/v1alpha1
metadata:
name: my-lvmcluster
namespace: openshift-storage (2)
---
apiVersion: policy.open-cluster-management.io/v1
kind: PlacementBinding
metadata:
name: binding-policy-lvmcluster-check
placementRef:
apiGroup: apps.open-cluster-management.io
kind: PlacementRule
name: placement-policy-lvmcluster-check
subjects:
- apiGroup: policy.open-cluster-management.io
kind: Policy
name: policy-lvmcluster-inform
---
apiVersion: apps.open-cluster-management.io/v1
kind: PlacementRule
metadata:
name: placement-policy-lvmcluster-check
spec:
clusterConditions:
- status: "True"
type: ManagedClusterConditionAvailable
clusterSelector:
matchExpressions:
- key: mykey
operator: In
values:
- myvalue
1 | The policy-template spec.remediationAction is overridden by the preceding parameter value for spec.remediationAction . |
2 | The namespace field must have the openshift-storage value. |
Create the policy by running the following command:
# oc create -f check-lvms-remove-policy.yaml -n lvms-policy-ns
Check the policy status by running the following command:
# oc get policy -n lvms-policy-ns
NAME REMEDIATION ACTION COMPLIANCE STATE AGE
policy-lvmcluster-delete enforce Compliant 15m
policy-lvmcluster-inform inform Compliant 15m
After both the policies are compliant, save the following YAML to a file with a name such as lvms-uninstall-policy.yaml
to create a policy to uninstall LVM Storage.
apiVersion: apps.open-cluster-management.io/v1
kind: PlacementRule
metadata:
name: placement-uninstall-lvms
spec:
clusterConditions:
- status: "True"
type: ManagedClusterConditionAvailable
clusterSelector:
matchExpressions:
- key: mykey
operator: In
values:
- myvalue
---
apiVersion: policy.open-cluster-management.io/v1
kind: PlacementBinding
metadata:
name: binding-uninstall-lvms
placementRef:
apiGroup: apps.open-cluster-management.io
kind: PlacementRule
name: placement-uninstall-lvms
subjects:
- apiGroup: policy.open-cluster-management.io
kind: Policy
name: uninstall-lvms
---
apiVersion: policy.open-cluster-management.io/v1
kind: Policy
metadata:
annotations:
policy.open-cluster-management.io/categories: CM Configuration Management
policy.open-cluster-management.io/controls: CM-2 Baseline Configuration
policy.open-cluster-management.io/standards: NIST SP 800-53
name: uninstall-lvms
spec:
disabled: false
policy-templates:
- objectDefinition:
apiVersion: policy.open-cluster-management.io/v1
kind: ConfigurationPolicy
metadata:
name: uninstall-lvms
spec:
object-templates:
- complianceType: mustnothave
objectDefinition:
apiVersion: v1
kind: Namespace
metadata:
name: openshift-storage
- complianceType: mustnothave
objectDefinition:
apiVersion: operators.coreos.com/v1
kind: OperatorGroup
metadata:
name: openshift-storage-operatorgroup
namespace: openshift-storage
spec:
targetNamespaces:
- openshift-storage
- complianceType: mustnothave
objectDefinition:
apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
name: lvms-operator
namespace: openshift-storage
remediationAction: enforce
severity: low
- objectDefinition:
apiVersion: policy.open-cluster-management.io/v1
kind: ConfigurationPolicy
metadata:
name: policy-remove-lvms-crds
spec:
object-templates:
- complianceType: mustnothave
objectDefinition:
apiVersion: apiextensions.k8s.io/v1
kind: CustomResourceDefinition
metadata:
name: logicalvolumes.topolvm.io
- complianceType: mustnothave
objectDefinition:
apiVersion: apiextensions.k8s.io/v1
kind: CustomResourceDefinition
metadata:
name: lvmclusters.lvm.topolvm.io
- complianceType: mustnothave
objectDefinition:
apiVersion: apiextensions.k8s.io/v1
kind: CustomResourceDefinition
metadata:
name: lvmvolumegroupnodestatuses.lvm.topolvm.io
- complianceType: mustnothave
objectDefinition:
apiVersion: apiextensions.k8s.io/v1
kind: CustomResourceDefinition
metadata:
name: lvmvolumegroups.lvm.topolvm.io
remediationAction: enforce
severity: high
Create the policy by running the following command:
# oc create -f lvms-uninstall-policy.yaml -ns lvms-policy-ns
You can configure a single-node OpenShift worker node as a Logical Volume Manager cluster. On the control-plane single-node OpenShift node, LVM Storage detects and uses the additional worker nodes when the new nodes become active in the cluster.
When you create a Logical Volume Manager cluster, |
Perform the following procedure to create a Logical Volume Manager cluster on a single-node OpenShift worker node.
You also can perform the same task by using the OKD web console. |
You have installed the OpenShift CLI (oc
).
You have logged in as a user with cluster-admin
privileges.
You installed LVM Storage in a single-node OpenShift cluster and have installed a worker node for use in the single-node OpenShift cluster.
Create the LVMCluster
custom resource (CR).
Save the following YAML in the lvmcluster.yaml
file:
apiVersion: lvm.topolvm.io/v1alpha1
kind: LVMCluster
metadata:
name: lvmcluster
spec:
storage:
deviceClasses: (1)
- name: vg1
fstype: ext4 (2)
default: true (3)
deviceSelector: (4)
paths:
- /dev/disk/by-path/pci-0000:87:00.0-nvme-1
- /dev/disk/by-path/pci-0000:88:00.0-nvme-1
optionalPaths:
- /dev/disk/by-path/pci-0000:89:00.0-nvme-1
- /dev/disk/by-path/pci-0000:90:00.0-nvme-1
thinPoolConfig:
name: thin-pool-1
sizePercent: 90
overprovisionRatio: 10
nodeSelector: (5)
nodeSelectorTerms:
- matchExpressions:
- key: app
operator: In
values:
- test1
1 | To create multiple device storage classes in the cluster, create a YAML array under deviceClasses for each required storage class.
Configure the local device paths of the disks as an array of values in the deviceSelector field.
When configuring multiple device classes, you must specify the device path for each device. |
2 | Set fstype to ext4 or xfs . By default, it is set to xfs if the setting is not specified. |
3 | Mandatory: The LVMCluster resource must contain a single default storage class. Set default: false for secondary device storage classes.
If you are upgrading the LVMCluster resource from a previous version, you must specify a single default device class. |
4 | Optional. To control or restrict the volume group to your preferred devices, you can manually specify the local paths of the devices in the deviceSelector section of the LVMCluster YAML. The paths section refers to devices the LVMCluster adds, which means those paths must exist. The optionalPaths section refers to devices the LVMCluster might add. You must specify at least one of paths or optionalPaths when specifying the deviceSelector section. If you specify paths , it is not mandatory to specify optionalPaths . If you specify optionalPaths , it is not mandatory to specify paths but at least one optional path must be present on the node. If you do not specify any paths, it will add all unused devices on the node. |
5 | Optional: To control what worker nodes the LVMCluster CR is applied to, specify a set of node selector labels.
The specified labels must be present on the node in order for the LVMCluster to be scheduled on that node. |
Create the LVMCluster
CR:
$ oc create -f lvmcluster.yaml
lvmcluster/lvmcluster created
The LVMCluster
resource creates the following system-managed CRs:
LVMVolumeGroup
Tracks individual volume groups across multiple nodes.
LVMVolumeGroupNodeStatus
Tracks the status of the volume groups on a node.
Verify that the LVMCluster
resource has created the StorageClass
, LVMVolumeGroup
, and LVMVolumeGroupNodeStatus
CRs.
|
Check that the LVMCluster
CR is in a ready
state by running the following command:
$ oc get lvmclusters.lvm.topolvm.io -o jsonpath='{.items[*].status.deviceClassStatuses[*]}'
{
"name": "vg1",
"nodeStatus": [
{
"devices": [
"/dev/nvme0n1",
"/dev/nvme1n1",
"/dev/nvme2n1"
],
"node": "kube-node",
"status": "Ready"
}
]
}
Check that the storage class is created:
$ oc get storageclass
NAME PROVISIONER RECLAIMPOLICY VOLUMEBINDINGMODE ALLOWVOLUMEEXPANSION AGE
lvms-vg1 topolvm.io Delete WaitForFirstConsumer true 31m
Check that the volume snapshot class is created:
$ oc get volumesnapshotclass
NAME DRIVER DELETIONPOLICY AGE
lvms-vg1 topolvm.io Delete 24h
Check that the LVMVolumeGroup
resource is created:
$ oc get lvmvolumegroup vg1 -o yaml
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: {}
Check that the LVMVolumeGroupNodeStatus
resource is created:
$ oc get lvmvolumegroupnodestatuses.lvm.topolvm.io kube-node -o yaml
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
You can add a storage class to an OKD cluster. A storage class describes a class of storage in the cluster and how the cluster dynamically provisions the persistent volumes (PVs) when the user specifies the storage class. A storage class describes the type of device classes, the quality-of-service level, the filesystem type, and other details.
Create a YAML file:
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
name: lvm-storageclass
parameters:
csi.storage.k8s.io/fstype: ext4
topolvm.io/device-class: vg1
provisioner: topolvm.io
reclaimPolicy: Delete
allowVolumeExpansion: true
volumeBindingMode: WaitForFirstConsumer
Save the file by using a name similar to the storage class name. For example, lvm-storageclass.yaml
.
Apply the YAML file by using the oc
command:
$ oc apply -f <file_name> (1)
1 | Replace <file_name> with the name of the YAML file. For example, lvm-storageclass.yaml . |
The cluster will create the storage class.
Verify that the cluster created the storage class by using the following command:
$ oc get storageclass <name> (1)
1 | Replace <name> with the name of the storage class. For example, lvm-storageclass . |
NAME PROVISIONER RECLAIMPOLICY VOLUMEBINDINGMODE ALLOWVOLUMEEXPANSION AGE
lvm-storageclass topolvm.io Delete WaitForFirstConsumer true 1s
You can provision persistent volume claims (PVCs) using the storage class that is created during the Operator installation. You can provision block and file PVCs, however, the storage is allocated only when a pod that uses the PVC is created.
LVM Storage provisions PVCs in units of 1 GiB. The requested storage is rounded up to the nearest GiB. |
Identify the StorageClass
that is created when LVM Storage is deployed.
The StorageClass
name is in the format, lvms-<device-class-name>
.
The device-class-name
is the name of the device class that you provided in the LVMCluster
of the Policy
YAML.
For example, if the deviceClass
is called vg1
, then the storageClass
name is lvms-vg1
.
The volumeBindingMode
of the storage class is set to WaitForFirstConsumer
.
To create a PVC where the application requires storage, save the following YAML to a file with a name such as pvc.yaml
.
# block pvc
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: lvm-block-1
namespace: default
spec:
accessModes:
- ReadWriteOnce
volumeMode: Block
resources:
requests:
storage: 10Gi
storageClassName: lvms-vg1
---
# file pvc
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: lvm-file-1
namespace: default
spec:
accessModes:
- ReadWriteOnce
volumeMode: Filesystem
resources:
requests:
storage: 10Gi
storageClassName: lvms-vg1
Create the PVC by running the following command:
# oc create -f pvc.yaml -ns <application_namespace>
The created PVCs remain in pending
state until you deploy the pods that use them.
When LVM Storage is installed using the OKD Web Console, you can monitor the cluster by using the Block and File dashboard in the console by default. However, when you use RHACM to install LVM Storage, you need to configure RHACM Observability to monitor all the single-node OpenShift clusters from one place.
You can monitor LVM Storage by viewing the metrics exported by the Operator on the RHACM dashboards and the alerts that are triggered.
Add the following topolvm
metrics to the allow
list:
topolvm_thinpool_data_percent
topolvm_thinpool_metadata_percent
topolvm_thinpool_size_bytes
Metrics are updated every 10 minutes or when there is a change in the thin pool, such as a new logical volume creation. |
When the thin pool and volume group are filled up, further operations fail and might lead to data loss. LVM Storage sends the following alerts about the usage of the thin pool and volume group when utilization crosses a certain value:
Alert | Description |
---|---|
|
This alert is triggered when both the volume group and thin pool utilization cross 75% on nodes. Data deletion or volume group expansion is required. |
|
This alert is triggered when both the volume group and thin pool utilization cross 85% on nodes. |
|
This alert is triggered when the thin pool data utilization in the volume group crosses 75% on nodes. Data deletion or thin pool expansion is required. |
|
This alert is triggered when the thin pool data utilization in the volume group crosses 85% on nodes. Data deletion or thin pool expansion is required. |
|
This alert is triggered when the thin pool metadata utilization in the volume group crosses 75% on nodes. Data deletion or thin pool expansion is required. |
|
This alert is triggered when the thin pool metadata utilization in the volume group crosses 85% on nodes. Data deletion or thin pool expansion is required. |
The OKD supports additional worker nodes for single-node OpenShift clusters on bare-metal user-provisioned infrastructure. LVM Storage detects and uses the new additional worker nodes when the nodes show up.
To scale the storage capacity of your configured worker nodes on a single-node OpenShift cluster, you can increase the capacity by adding disks.
You have additional unused disks on each single-node OpenShift cluster to be used by LVM Storage.
Log in to OKD console of the single-node OpenShift cluster.
From the Operators → Installed Operators page, click on the LVM Storage Operator in the openshift-storage
namespace.
Click on the LVMCluster tab to list the LVMCluster
CR created on the cluster.
Select Edit LVMCluster from the Actions drop-down menu.
Click on the YAML tab.
Edit the LVMCluster
CR YAML to add the new device path in the deviceSelector
section:
In case the |
apiVersion: lvm.topolvm.io/v1alpha1
kind: LVMCluster
metadata:
name: my-lvmcluster
spec:
storage:
deviceClasses:
- name: vg1
default: true
deviceSelector: (1)
paths:
- /dev/disk/by-path/pci-0000:87:00.0-nvme-1
- /dev/disk/by-path/pci-0000:88:00.0-nvme-1
optionalPaths:
- /dev/disk/by-path/pci-0000:89:00.0-nvme-1
- /dev/disk/by-path/pci-0000:90:00.0-nvme-1
thinPoolConfig:
name: thin-pool-1
sizePercent: 90
overprovisionRatio: 10
1 | Optional. To control or restrict the volume group to your preferred devices, you can manually specify the local paths of the devices in the deviceSelector section of the LVMCluster YAML. The paths section refers to devices the LVMCluster adds, which means those paths must exist. The optionalPaths section refers to devices the LVMCluster might add. You must specify at least one of paths or optionalPaths when specifying the deviceSelector section. If you specify paths , it is not mandatory to specify optionalPaths . If you specify optionalPaths , it is not mandatory to specify paths but at least one optional path must be present on the node. If you do not specify any paths, it will add all unused devices on the node. |
You can scale the storage capacity of your configured worker nodes on a single-node OpenShift cluster using RHACM.
You have access to the RHACM cluster using an account with cluster-admin
privileges.
You have additional unused devices on each single-node OpenShift cluster that LVM Storage can use.
Log in to the RHACM CLI using your OKD credentials.
Find the device that you want to add. The device to be added needs to match with the device name and path of the existing devices.
To add capacity to the single-node OpenShift cluster, edit the deviceSelector
section of the existing policy YAML, for example, policy-lvms-operator.yaml
.
In case the |
apiVersion: apps.open-cluster-management.io/v1
kind: PlacementRule
metadata:
name: placement-install-lvms
spec:
clusterConditions:
- status: "True"
type: ManagedClusterConditionAvailable
clusterSelector:
matchExpressions:
- key: mykey
operator: In
values:
- myvalue
---
apiVersion: policy.open-cluster-management.io/v1
kind: PlacementBinding
metadata:
name: binding-install-lvms
placementRef:
apiGroup: apps.open-cluster-management.io
kind: PlacementRule
name: placement-install-lvms
subjects:
- apiGroup: policy.open-cluster-management.io
kind: Policy
name: install-lvms
---
apiVersion: policy.open-cluster-management.io/v1
kind: Policy
metadata:
annotations:
policy.open-cluster-management.io/categories: CM Configuration Management
policy.open-cluster-management.io/controls: CM-2 Baseline Configuration
policy.open-cluster-management.io/standards: NIST SP 800-53
name: install-lvms
spec:
disabled: false
remediationAction: enforce
policy-templates:
- objectDefinition:
apiVersion: policy.open-cluster-management.io/v1
kind: ConfigurationPolicy
metadata:
name: install-lvms
spec:
object-templates:
- complianceType: musthave
objectDefinition:
apiVersion: v1
kind: Namespace
metadata:
labels:
openshift.io/cluster-monitoring: "true"
pod-security.kubernetes.io/enforce: privileged
pod-security.kubernetes.io/audit: privileged
pod-security.kubernetes.io/warn: privileged
name: openshift-storage
- complianceType: musthave
objectDefinition:
apiVersion: operators.coreos.com/v1
kind: OperatorGroup
metadata:
name: openshift-storage-operatorgroup
namespace: openshift-storage
spec:
targetNamespaces:
- openshift-storage
- complianceType: musthave
objectDefinition:
apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
name: lvms
namespace: openshift-storage
spec:
installPlanApproval: Automatic
name: lvms-operator
source: redhat-operators
sourceNamespace: openshift-marketplace
remediationAction: enforce
severity: low
- objectDefinition:
apiVersion: policy.open-cluster-management.io/v1
kind: ConfigurationPolicy
metadata:
name: lvms
spec:
object-templates:
- complianceType: musthave
objectDefinition:
apiVersion: lvm.topolvm.io/v1alpha1
kind: LVMCluster
metadata:
name: my-lvmcluster
namespace: openshift-storage
spec:
storage:
deviceClasses:
- name: vg1
default: true
deviceSelector: (1)
paths:
- /dev/disk/by-path/pci-0000:87:00.0-nvme-1
- /dev/disk/by-path/pci-0000:88:00.0-nvme-1
optionalPaths:
- /dev/disk/by-path/pci-0000:89:00.0-nvme-1
- /dev/disk/by-path/pci-0000:90:00.0-nvme-1
thinPoolConfig:
name: thin-pool-1
sizePercent: 90
overprovisionRatio: 10
nodeSelector:
nodeSelectorTerms:
- matchExpressions:
- key: app
operator: In
values:
- test1
remediationAction: enforce
severity: low
1 | Optional. To control or restrict the volume group to your preferred devices, you can manually specify the local paths of the devices in the deviceSelector section of the LVMCluster YAML. The paths section refers to devices the LVMCluster adds, which means those paths must exist. The optionalPaths section refers to devices the LVMCluster might add. You must specify at least one of paths or optionalPaths when specifying the deviceSelector section. If you specify paths , it is not mandatory to specify optionalPaths . If you specify optionalPaths , it is not mandatory to specify paths but at least one optional path must be present on the node. If you do not specify any paths, it will add all unused devices on the node. |
Edit the policy by running the following command:
# oc edit -f policy-lvms-operator.yaml -ns lvms-policy-ns (1)
1 | The policy-lvms-operator.yaml is the name of the existing policy. |
This uses the new disk specified in the LVMCluster
CR to provision storage.
To leverage the new storage after adding additional capacity, you can expand existing persistent volume claims (PVCs) with LVM Storage.
Dynamic provisioning is used.
The controlling StorageClass
object has allowVolumeExpansion
set to true
.
Modify the .spec.resources.requests.storage
field in the desired PVC resource to the new size by running the following command:
oc patch <pvc_name> -n <application_namespace> -p '{ "spec": { "resources": { "requests": { "storage": "<desired_size>" }}}}'
Watch the status.conditions
field of the PVC to see if the resize has completed. OKD adds the Resizing
condition to the PVC during expansion, which is removed after the expansion completes.
Currently, it is not possible to upgrade from OpenShift Data Foundation Logical Volume Manager Operator 4.11 to LVM Storage 4.12 on single-node OpenShift clusters.
The data will not be preserved during this process. |
Back up any data that you want to preserve on the persistent volume claims (PVCs).
Delete all PVCs provisioned by the OpenShift Data Foundation Logical Volume Manager Operator and their pods.
Reinstall LVM Storage on OKD 4.12.
Recreate the workloads.
Copy the backup data to the PVCs created after upgrading to 4.12.
You can take volume snapshots of persistent volumes (PVs) that are provisioned by LVM Storage. You can also create volume snapshots of the cloned volumes. Volume snapshots help you to do the following:
Back up your application data.
Volume snapshots are located on the same devices as the original data. To use the volume snapshots as backups, you need to move the snapshots to a secure location. You can use OpenShift API for Data Protection backup and restore solutions. |
Revert to a state at which the volume snapshot was taken.
You can create volume snapshots based on the available capacity of the thin pool and the overprovisioning limits.
LVM Storage creates a VolumeSnapshotClass
with the lvms-<deviceclass-name>
name.
You ensured that the persistent volume claim (PVC) is in Bound
state. This is required for a consistent snapshot.
You stopped all the I/O to the PVC before taking the snapshot.
Log in to the single-node OpenShift for which you need to run the oc
command.
Save the following YAML to a file with a name such as lvms-vol-snapshot.yaml
.
apiVersion: snapshot.storage.k8s.io/v1
kind: VolumeSnapshot
metadata:
name: lvm-block-1-snap
spec:
volumeSnapshotClassName: lvms-vg1
source:
persistentVolumeClaimName: lvm-block-1
Create the snapshot by running the following command in the same namespace as the PVC:
# oc create -f lvms-vol-snapshot.yaml
A read-only copy of the PVC is created as a volume snapshot.
When you restore a volume snapshot, a new persistent volume claim (PVC) is created. The restored PVC is independent of the volume snapshot and the source PVC.
The storage class must be the same as that of the source PVC.
The size of the requested PVC must be the same as that of the source volume of the snapshot.
A snapshot must be restored to a PVC of the same size as the source volume of the snapshot. If a larger PVC is required, you can resize the PVC after the snapshot is restored successfully. |
Identify the storage class name of the source PVC and volume snapshot name.
Save the following YAML to a file with a name such as lvms-vol-restore.yaml
to restore the snapshot.
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
name: lvm-block-1-restore
spec:
accessModes:
- ReadWriteOnce
volumeMode: Block
Resources:
Requests:
storage: 2Gi
storageClassName: lvms-vg1
dataSource:
name: lvm-block-1-snap
kind: VolumeSnapshot
apiGroup: snapshot.storage.k8s.io
Create the policy by running the following command in the same namespace as the snapshot:
# oc create -f lvms-vol-restore.yaml
You can delete volume snapshots resources and persistent volume claims (PVCs).
Delete the volume snapshot resource by running the following command:
# oc delete volumesnapshot <volume_snapshot_name> -n <namespace>
When you delete a persistent volume claim (PVC), the snapshots of the PVC are not deleted. |
To delete the restored volume snapshot, delete the PVC that was created to restore the volume snapshot by running the following command:
# oc delete pvc <pvc_name> -n <namespace>
A clone is a duplicate of an existing storage volume that can be used like any standard volume.
You create a clone of a volume to make a point-in-time copy of the data. A persistent volume claim (PVC) cannot be cloned with a different size.
The cloned PVC has write access. |
You ensured that the PVC is in Bound
state. This is required for a consistent snapshot.
You ensured that the StorageClass
is the same as that of the source PVC.
Identify the storage class of the source PVC.
To create a volume clone, save the following YAML to a file with a name such as lvms-vol-clone.yaml
:
apiVersion: v1
kind: PersistentVolumeClaim
Metadata:
name: lvm-block-1-clone
Spec:
storageClassName: lvms-vg1
dataSource:
name: lvm-block-1
kind: PersistentVolumeClaim
accessModes:
- ReadWriteOnce
volumeMode: Block
Resources:
Requests:
storage: 2Gi
Create the policy in the same namespace as the source PVC by running the following command:
# oc create -f lvms-vol-clone.yaml
When LVM Storage is unable to automatically resolve a problem, use the must-gather tool to collect the log files and diagnostic information so that you or the Red Hat Support can review the problem and determine a solution.
Run the must-gather command from the client connected to LVM Storage cluster by running the following command:
$ oc adm must-gather --image=registry.redhat.io/lvms4/lvms-must-gather-rhel8:v4 --dest-dir=<directory-name>
The sample LVMCluster
custom resource (CR) describes all the fields in the YAML file.
apiVersion: lvm.topolvm.io/v1alpha1
kind: LVMCluster
metadata:
name: my-lvmcluster
spec:
tolerations:
- effect: NoSchedule
key: xyz
operator: Equal
value: "true"
storage:
deviceClasses: (1)
- name: vg1 (2)
default: true
nodeSelector: (3)
nodeSelectorTerms: (4)
- matchExpressions:
- key: mykey
operator: In
values:
- ssd
deviceSelector: (5)
paths:
- /dev/disk/by-path/pci-0000:87:00.0-nvme-1
- /dev/disk/by-path/pci-0000:88:00.0-nvme-1
optionalPaths:
- /dev/disk/by-path/pci-0000:89:00.0-nvme-1
- /dev/disk/by-path/pci-0000:90:00.0-nvme-1
thinPoolConfig: (6)
name: thin-pool-1 (7)
sizePercent: 90 (8)
overprovisionRatio: 10 (9)
status:
deviceClassStatuses: (10)
- name: vg1
nodeStatus: (11)
- devices: (12)
- /dev/nvme0n1
- /dev/nvme1n1
- /dev/nvme2n1
node: my-node.example.com (13)
status: Ready (14)
ready: true (15)
state: Ready (16)
1 | The LVM volume groups to be created on the cluster. Currently, only a single deviceClass is supported. |
2 | The name of the LVM volume group to be created on the nodes. |
3 | The nodes on which to create the LVM volume group. If the field is empty, all nodes are considered. |
4 | A list of node selector requirements. |
5 | A list of device paths which is used to create the LVM volume group. If this field is empty, all unused disks on the node will be used. |
6 | The LVM thin pool configuration. |
7 | The name of the thin pool to be created in the LVM volume group. |
8 | The percentage of remaining space in the LVM volume group that should be used for creating the thin pool. |
9 | The factor by which additional storage can be provisioned compared to the available storage in the thin pool. |
10 | The status of the deviceClass . |
11 | The status of the LVM volume group on each node. |
12 | The list of devices used to create the LVM volume group. |
13 | The node on which the deviceClass was created. |
14 | The status of the LVM volume group on the node. |
15 | This field is deprecated. |
16 | The status of the LVMCluster . |