Longhorn
Longhorn is a distributed block storage system for Kubernetes. Longhorn is cloud native storage because it is built using Kubernetes and container primitives.
Longhorn is lightweight, reliable, and powerful. You can install Longhorn on an existing Kubernetes cluster with one kubectl apply command or using Helm charts. Once Longhorn is installed, it adds persistent volume support to the Kubernetes cluster.
Longhorn implements distributed block storage using containers and microservices. Longhorn creates a dedicated storage controller for each block device volume and synchronously replicates the volume across multiple replicas stored on multiple nodes. The storage controller and replicas are themselves orchestrated using Kubernetes. Here are some notable features of Longhorn:
- Enterprise-grade distributed storage with no single point of failure
- Incremental snapshot of block storage
- Backup to secondary storage (NFSv4 or S3-compatible object storage) built on efficient change block detection
- Recurring snapshot and backup
- Automated non-disruptive upgrade. You can upgrade the entire Longhorn software stack without disrupting running volumes!
- Intuitive GUI dashboard
You can read more technical details of Longhorn here.
Current Status
The latest release of Longhorn is
Build Status
- Engine:
- Manager:
- Instance Manager:
- Share Manager:
- Backing Image Manager:
- UI:
- Test:
Release Status
| Release | Version | Type |
|---|---|---|
| 1.2 | 1.2.3 | Stable, Latest |
| 1.1 | 1.1.3 | Stable, Latest |
Get Involved
Community Meeting and Office Hours
Hosted by the core maintainers of Longhorn: 4th Friday of the every month at 09:00 (CET) or 16:00 (CST) at https://community.cncf.io/longhorn-community/.
Longhorn Mailing List
Stay up to date on the latest news and events: https://lists.cncf.io/g/cncf-longhorn
You can read more about the community and its events here: https://github.com/longhorn/community
Source code
Longhorn is 100% open source software. Project source code is spread across a number of repos:
| Component | What it does | GitHub repo |
|---|---|---|
| Longhorn Backing Image Manager | Backing image download, sync, and deletion in a disk | longhorn/backing-image-manager |
| Longhorn Engine | Core controller/replica logic | longhorn/longhorn-engine |
| Longhorn Instance Manager | Controller/replica instance lifecycle management | longhorn/longhorn-instance-manager |
| Longhorn Manager | Longhorn orchestration, includes CSI driver for Kubernetes | longhorn/longhorn-manager |
| Longhorn Share Manager | NFS provisioner that exposes Longhorn volumes as ReadWriteMany volumes | longhorn/longhorn-share-manager |
| Longhorn UI | The Longhorn dashboard | longhorn/longhorn-ui |
Requirements
For the installation requirements, refer to the Longhorn documentation.
Installation
Longhorn can be installed on a Kubernetes cluster in several ways:
Documentation
The official Longhorn documentation is here.
Community
Longhorn is open source software, so contributions are greatly welcome. Please read Code of Conduct and Contributing Guideline before contributing.
Contributing code is not the only way of contributing. We value feedbacks very much and many of the Longhorn features are originated from users' feedback. If you have any feedbacks, feel free to file an issue and talk to the developers at the CNCF #longhorn Slack channel.
If having any discussion, feedbacks, requests, issues or security reports, please follow below ways. We also have a CNCF Slack channel: longhorn for discussion.
Discussions or Feedbacks
If having any discussions or feedbacks, feel free to file a discussion.
Requests or Issues
If having any issues, feel free to file an issue. We have a weekly community issue review meeting to review all reported issues or enhancement requests.
When creating a bug issue, please help upload the support bundle to the issue or send to longhorn-support-bundle.
Report Vulnerabilities
If having any vulnerabilities found, please report to longhorn-security.
License
Copyright (c) 2014-2021 The Longhorn Authors
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
Longhorn is a CNCF Incubating Project
