Fundamental understanding problem -- pods cannot be scheduled on nodes that DON'T run longhorn

Longhorn
1

Hi all,

I seem to have not understood something basic about longhorn. I have 3 dedicated nodes for longhorn that have excessive storage. No other pods than longhorn should run there. I have 9 other worker nodes for all other pods.
Now when I create a PVC with the longhorn storage class and create a pod that mounts this, the pod is scheduled on a node that is NOT one of the 3 longhorn nodes. Upon pod creation, it states that it cannot attach the volume due to the node not being found.

I thought this should work. With my current scenario, I can only use PVC with pods that I schedule on one of the 3 longhorn nodes, but that for sure can’t be intentional? That would basically be the same as hostPath volumes…

2

In order to achieve your desired usecase, some Longhorn components need to run on the 9 worker nodes to prepare/create/attach/mount Longhorn volume for your worker nodes. See this doc for more details Tip: Set Longhorn To Only Use Storage On A Specific Set Of Nodes | The Longhorn Knowledge Base