Topolvm-Operator

Topolvm-Operator is an open source cloud-native local storage orchestrator for Kubernetes, which bases on topolvm.

Supported environments

• Kubernetes: 1.20, 1.19
• Node OS: Linux with LVM2
• Filesystems: ext4, xfs

The CSIStorageCapacity feature gate should be turned on

Features

• Orchestrate topolvm
• Prepare volume group
• Volume group dynamic expand
• Perception of storage topology
• Volume capacity limit
• PVC snapshot
• Prometheus metric and alarm
• Auto discover available devices

OperatorHub.io

Topolvm Operator had been shared in operatorhub.io home.

Planned features

• Raid of volume group
• Manage volume group that user created

Components

• operator: orchestrate topolvm include TopolvmCluster controller and ConfigMap controller
• preparevg: prepare volume group on each node

Diagram

A diagram of components and the how they work see below:

How components work

1. Topolvm-operator watch the TopolvmCluster(CRD)
2. Topolvm-operator watch the operator-setting ConfigMap
3. Topolvm-operator start discover devices Daemonset
4. Topolvm-operator start ConfigMap controller to watch lvmd ConfigMap if TopolvmCluster created
5. TopolvmCluster controller create preparevg Job,Topolvm-controller Deployment depend on TopolvmCluster
6. preparevg Job on specific node check disk that provided in TopolvmCluster and create volume group, if volume group created successfully and then create lvmd ConfigMap for the node
7. ConfigMap controller finds the new lvmd ConfigMap then create Topolvm-node Deployment
8. TopolvmCluster controller update TopolvmCluster status

Getting started and Documentation

docs directory contains documents about installation and specifications

Topolvm-operator vs Other local storage Implement

	nfs	rook ceph	longhorn	host path	topolvm
filesystem	yes	yes	yes	yes	yes
filesystem type	nfs	ext4/xfs	driver specific	ext4/xfs	ext4/xfs
block	no	yes (rbd)	yes	no	yes
bandwidth	standard	high	high	high	high
IOPS	standard	standard	standard	high	high
latency	standard	standard	standard	low	low
snapshot	no	yes	yes	no	yes
clone	no	yes	no	no	no
quota	no	yes	yes	no	yes
access mod	ReadWriteOnce ReadOnlyMany ReadWriteMany	ReadWriteOnce ReadOnlyMany ReadWriteMany	ReadWriteOnce ReadOnlyMany	ReadWriteOnce	ReadWriteOnce ReadWriteOncePod
resizing	yes	yes	yes	yes	yes
data redundancy	Hardware RAID	yes	yes	Hardware RAID	Hardware RAID
protocol type	nfs	rados	iscsi	fs	lvm
ease of maintainess	driver specific	high maintainess effort	medium	medium	ops-free
usage scenarios	general storage	extremly scalability	container attach storage	temporary data	high performance block device for cloudnative applications

Topolvm

topolvm-operator is based on topolvm, we fork topolvm/topolvm and do some enhancements.

see alauda/topolvm

the enhancements are below:

• remove topolvm-scheduler
• lvmd containerized
• add new feature snapshot

Docker images

• topolvm-operator alaudapublic/topolvm-operator
• topolvm alaudapublic/topolvm

Report a Bug

For filing bugs, suggesting improvements, or requesting new features, please open an issue.