FAQ

Reasons why BlockDevice resources aren’t created in the cluster

Most often, BlockDevice resources are not created because the available devices do not pass the controller’s filters. Ensure that the devices meet the selection criteria.

Reasons why LVMVolumeGroup resources aren’t created in the cluster

• Absence of BlockDevice: The controller will not create an LVMVolumeGroup if there are no BlockDevice resources in the cluster specified in its specification.
• Absence of a tag: If BlockDevice resources are present but the LVMVolumeGroup is missing, check that the corresponding LVM group on the node has the tag storage.deckhouse.io/enabled=true.

Reasons why after deleting the LVMVolumeGroup, the resource and Volume Group remain

This situation is possible in two cases:

1. There are logical volumes in the Volume Group — the controller is not responsible for deleting logical volumes on the node, so if there are any logical volumes in the Volume Group created via the resource, they must be manually deleted. After that, both the LVMVolumeGroup resource and the Volume Group itself (including physical volumes) will be automatically deleted.

2. The resource has the annotation storage.deckhouse.io/deletion-protection — this annotation protects the resource from deletion, along with the associated Volume Group. Remove the annotation with the command:

   d8 k annotate lvg <resource-name> storage.deckhouse.io/deletion-protection-
   

   After that, the LVMVolumeGroup resource and the corresponding Volume Group will be automatically deleted.

Reasons for failed attempts to create a Volume Group using the LVMVolumeGroup resource

Most likely, the resource did not pass validation by the controller (unlike the Kubernetes schema). The reason can be found in the status.message field of the LVMVolumeGroup resource or in the controller logs. Check that the specified BlockDevice resources meet the conditions:

• The consumable field is set to true.
• For spec.type: Local, all BlockDevice resources belong to the same node.
• Current names of BlockDevice resources are used.

Behavior of the LVMVolumeGroup resource when one of the devices in the Volume Group is disabled

The LVMVolumeGroup resource remains as long as the corresponding LVM group exists. When a device becomes unavailable, the group enters an error state, which is reflected in the status field.

After the device is restored, the group returns to the Healthy status, and the resource status is automatically updated.

Transferring management of an existing Volume Group on the node to the controller

Add the tag storage.deckhouse.io/enabled=true to the desired Volume Group:

vgchange myvg-0 --addtag storage.deckhouse.io/enabled=true

The controller will create the corresponding LVMVolumeGroup resource and take over management of the group.

Disabling tracking of the LVM Volume Group by the controller

Remove the tag storage.deckhouse.io/enabled=true:

vgchange myvg-0 --deltag storage.deckhouse.io/enabled=true

The controller will stop tracking and delete the associated LVMVolumeGroup resource.

Reasons for automatic setting of the tag storage.deckhouse.io/enabled=true on the Volume Group

The controller adds the tag when creating the Volume Group through the LVMVolumeGroup resource.

When migrating from the linstor module to sds-node-configurator and sds-replicated-volume, all linstor-* tags are replaced with storage.deckhouse.io/enabled=true to transfer management to the new logic.

Using the LVMVolumeGroupSet resource to create LVMVolumeGroup

The LVMVolumeGroupSet resource allows template-based creation of LVMVolumeGroup on nodes. Currently, the PerNode strategy is supported — one resource per node that matches the selector.

Example specification of LVMVolumeGroupSet:

apiVersion: storage.deckhouse.io/v1alpha1
kind: LVMVolumeGroupSet
metadata:
  name: my-lvm-volume-group-set
  labels:
    my-label: my-value
spec:
  strategy: PerNode
  nodeSelector:
    matchLabels:
      node-role.kubernetes.io/worker: ""
  lvmVolumeGroupTemplate:
    metadata:
      labels:
        my-label-for-lvg: my-value-for-lvg
    spec:
      type: Local
      blockDeviceSelector:
        matchLabels:
          status.blockdevice.storage.deckhouse.io/model: <model>
      actualVGNameOnTheNode: <VG-name-on-the-node>

Labels added by the controller to BlockDevice resources

• status.blockdevice.storage.deckhouse.io/type: LVM type.
• status.blockdevice.storage.deckhouse.io/fstype: File system type.
• status.blockdevice.storage.deckhouse.io/pvuuid: Physical volume (PV) UUID.
• status.blockdevice.storage.deckhouse.io/vguuid: Volume group (VG) UUID.
• status.blockdevice.storage.deckhouse.io/partuuid: Partition UUID.
• status.blockdevice.storage.deckhouse.io/lvmvolumegroupname: Name of the LVMVolumeGroup resource.
• status.blockdevice.storage.deckhouse.io/actualvgnameonthenode: Name of the LVM Volume Group on the node.
• status.blockdevice.storage.deckhouse.io/wwn: WWN (World Wide Name) of the device.
• status.blockdevice.storage.deckhouse.io/serial: Serial number of the device.
• status.blockdevice.storage.deckhouse.io/size: Size of the device.
• status.blockdevice.storage.deckhouse.io/model: Model of the device.
• status.blockdevice.storage.deckhouse.io/rota: Rotational device flag.
• status.blockdevice.storage.deckhouse.io/hotplug: Hotplug capability.
• status.blockdevice.storage.deckhouse.io/machineid: Identifier of the machine where the device is installed.