OpenEBS, volumes, and kuberenetes upgrades

November 25, 2019 111 views
DigitalOcean Managed Kubernetes Kubernetes

I installed the OpenEBS application from the marketplace onto a Kubernetes cluster. Following the instructions from MayaData, I’ve created three unformatted volumes of the same size and attached them to three different nodes in my cluster. I’ve created a StoragePool, and StorageClasses, and PersistentVolumeClaims against those. I can mount the OpenEBS PersistentVolumes into my containers giving me replicated storage on my cluster. So far, so good.

My question is, what will happen to those volumes when I upgrade my cluster to a new version of Kubernetes? DigitalOcean’s software will create new nodes, but will it attach volumes to those nodes in the same way it did when I created them (e.g., one volume per node)? Will it even attach them at all? I’m a bit scared to find out.

edited by bobbyiliev
1 Answer

Hi @bkoehn. I work for MayaData. I am trying to make a similar setup and trying out the use case. In general, if an old node is replaced with a new node, there are few manual steps to make the cStor pool and volume online. This can be done only when the unique id (BD name) of the underlying disk is not changed. So to understand about the attached block device information, could you give me the output of udevadm info <device_path> (For example,udevadm info /dev/sdb) of all attached blockdevices from all the worker nodes, please?

Have another answer? Share your knowledge.