Posts tagged: longhorn

All posts with the tag "longhorn"

2 posts latest post 2025-08-15
Publishing rhythm
Aug 2025 | 1 posts

Interesting longhorn storage performance test, author does highlight right away that this is a simulation and not a REAL test. I did not fully understand the storage semantics before reading through this.

This is an important distinction for applications that use sqlite or a tool on top of sqlite such as diskcache. With sqlite it is not recomended to run over nfs due to missing required file locking mechanisms.

Longhorn storage still provides a lot of benefits to these applications as the storage is automatically replicated, if the node that your application is running on goes offline a new pod will start on an existing node. If you have planned downtime, you can cordon and drain a node. Since the data is available in another location you will be able to start a new pod on anther node. barring your PodDisruptionBudget settings, taints, and affinity, this may happen automatically.

Changing k8s Storage Class - Migration Job

I’m setting up longhorn in my homelab, and I ran into an issue where I initially setup some pvcs under longhorn, and later realized that to get longhorn to snapshot and backup I needed to hand edit volumes after the fact or change storage class. I’m all in on gitops so option 1 was not an option. So changing storageclass it is.

Now the issue is that you CANNOT mutate storageclass on a provisioned pvc, it is an immutable attribute.

This migration job will create a new pvc with the new storageclass and move the data from the old pvc to the new pvc.

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