Create StorageClass(s)

This document provides step-by-step instructions on creating a custom StorageClass for Local PV LVM, including detailed explanations of supported parameters and their usage. It covers standard and LVM-specific parameters, their development status, E2E test coverage, and how to configure scheduling logic like SpaceWeighted, CapacityWeighted, or VolumeWeighted.

$ cat sc.yaml

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: openebs-lvmpv
parameters:
  storage: "lvm"
  volgroup: "lvmvg"
provisioner: local.csi.openebs.io

Refer Storage Classes to know all the supported parameters for Local PV LVM.

StorageClass Parameters Conformance Matrix#

The following matrix shows standard StorageClass parameters for Local PV LVM.

Standard StorageClass Parameters#

Parameter	Values		Development Status	E2E Coverage
allowVolumeExpansion	true		Supported	Yes (Test coverage exist for ext4 & xfs)
allowVolumeExpansion	false		Supported	Yes (Test coverage exist for ext4 & xfs)
MountOptions	Options supported by filesystem		Supported	Pending
VolumeBindingMode	Immediate		Supported	Yes
VolumeBindingMode	WaitForFirstConsumer		Supported	Yes
Reclaim Policy	Retain		Supported	Yes (Test coverage exist for Delete reclaim policy)
Reclaim Policy	Delete		Supported	Yes (Test coverage exist for Delete reclaim policy)
allowedTopologies	-		Supported	Yes
Parameters	Passing Secrets		No Use Case	NA
	fsType	ext2	Supported	Yes (Test coverage exist for ext4 & xfs)
		ext3
		ext4
		xfs
		btrfs

LVM Supported StorageClass Parameters#

Parameter	Values		Development Status	E2E Coverage
Parameters	shared	yes	Supported	Yes
	vgpattern	Regular expression of volume group name	Supported	Yes
	volgroup	Name of volume group	Supported	Yes
	thinProvision	yes	Supported	Yes
	scheduler	SpaceWeighted or CapacityWeighted or VolumeWeighted	Supported	Pending

StorageClass with Scheduler Parameters#

The Local PV LVM Driver supports three types of scheduling logic: SpaceWeighted, VolumeWeighted, and CapacityWeighted (Supported from lvm-driver: v0.9.0).

Add the scheduler parameter in storage class and give its value accordingly.

parameters:
  storage: "lvm"
  volgroup: "lvmvg" 
  scheduler: "CapacityWeighted" ## or "VolumeWeighted"

SpaceWeighted is the default scheduler in the Local PV LVM driver, so even if we do not use the scheduler parameter in storageclass, the driver will pick the node where there is a vg with the highest free space adhering to the volgroup/vgpattern parameter.

If CapacityWeighted scheduler is used, then the driver will pick the node containing vg that has the least allocated storage in terms of capacity.

If VolumeWeighted scheduler is used, then the driver will pick the node containing vg (adhering to vgpattern/volgroup parameter) that has the least number of volumes provisioned on it.

Support#

If you encounter issues or have a question, file a Github issue, or talk to us on the #openebs channel on the Kubernetes Slack server.