Add Longhorn to set up persistent storage

[Christian-Rau]

Longhorn is a great tool used to set up and manage persistent data storage in any cluster. It comes with a simple GUI.

https://github.com/longhorn/longhorn

Thank you!

[alexellis]

I'm open to someone working on a PR for this, can you give some details on the installation method? Does it use helm?

Is it available for any other architecture other than x86_64? Potentially ARM64 but not ARMHF?

[Christian-Rau]

Sounds great. For this purpose, there are 2 installation methods.

• kubectl
• Helm

Installation of Longhorn on K3s clusters, require some extra setup. According to the docs:

• Longhorn v0.7.0 or higher.
• open-iscsi or iscsiadm installed on the node.

The helm charts are located here: https://github.com/longhorn/charts

Helm 2: helm install ./longhorn/chart --name longhorn --namespace longhorn-system

Helm 3: When installing Longhorn with Helm 3, the namespace is created separately.

kubectl create namespace longhorn-system
helm install longhorn ./longhorn/chart/ --namespace longhorn-system

The yaml file for kubectl is here: longhorn.yaml

ARM64 support According to the 1.1.0 release notes (latest stable at the time of writing): ARM64 support (experimental) Longhorn now supports ARM64 architecture in addition to AMD64. You can deploy Longhorn as usual in ARM64 without any modification. What exactly as usual means I will try to look into.

Hope it helps. Edit: added link to open-iscsi and added info about ARM64 support.

[Christian-Rau]

I would like work on PR on this, I just don't have the skills to do it. However, I would like to learn how to do it.

[alexellis]

open-iscsi or iscsiadm installed on the node

This is where users are likely to find this confusing.

Is there any documentation for adding that package to kind or k3s?

[Christian-Rau]

sorry for late reply.

Rancher docs always confuse me... so they did again.

It seems there is an open-iscsi installer that does the trick. It enables the iscsi deamon as well.

kubectl apply -f https://raw.githubusercontent.com/longhorn/longhorn/v1.1.0/deploy/iscsi/longhorn-iscsi-installation.yaml

Then we need to make sure each node has a NFSv4 client installed. and ext4 or XFS file system is supported. and curl, findmnt, grep, awk, blkid, lsblk must be installed.

This script should check of the above req. curl -sSfL https://raw.githubusercontent.com/longhorn/longhorn/v1.1.0/scripts/environment_check.sh | bash

Edit: updated the requirements section