DOKS node's persistent disk.

Question

I’m currently building an application using the DOKS. I have a question regarding Persistance Volumes and node’s disks and cluster upgrades. The nodes is obviously a droplet instances that has persistent disks.

The questions:

Can I utilize the node’s disk for my Persistence Volume with something for example Longhorn for Kubernetes Storage?
How do DigitalOcean handle upgrades? Do the nodes in the cluster recreated?
Will my data on the node’s disk gone after upgrades (manually or automatically)

I mean you had nodes with 160GB+ of disk. If I can’t utilize it because the data would be gone because the nodes are recreated on upgrades that’s a bummer.

Bobby · Answer

Hi there,

As far as I can tell, it appears that using Longhorn with DOKS might not be feasible due to specific compatibility issues as discussed in this Longhorn GitHub issue.

Given the challenges with using Longhorn in DOKS, here’s an overview of some alternatives, including running Rook/Ceph on DOKS, which might suit your needs better.

DigitalOcean Spaces for Object Storage

Use Cases: Ideal for storing and serving large amounts of unstructured data like images, videos, backups, etc. Spaces is an S3-compatible service, scalable and secure for such requirements:

https://docs.digitalocean.com/products/spaces/

DigitalOcean Block Storage

Capabilities: Offers robust, high-performance storage but with a limitation - a Block Storage volume can be mounted to only one node at a time.
Ideal Scenarios: Best suited for databases or single-node applications needing reliable, persistent storage.

https://docs.digitalocean.com/products/kubernetes/how-to/add-volumes/

Running Rook/Ceph on DOKS

Overview: For scenarios requiring shared storage accessible across multiple nodes, running Rook/Ceph on DOKS can be an effective solution.
Rook/Ceph: It is an open-source storage platform that provides scalable and redundant storage using commodity hardware, and it’s well-suited for Kubernetes environments.
DigitalOcean’s Storage Offering: Here is a great article by Jack Pearce, that covers the whole setup process and describes the block storage limitation.
Rook/Ceph Advantage: By deploying Rook with Ceph within your DOKS environment, you can create a more flexible storage solution that allows pods across different nodes to share storage, overcoming the single-node limitation of standard block storage.

If you have further questions or need more detailed advice, the community is here to help!

Best,

Bobby