GCE Persistent Disk Same zone as Kubernetes Pod?

Question

I am trying to mount a GCE persistent disk in a kubernetes pod via the deployment object yaml. I am observing this behavior that as long as the node (on which the pod resides) is in the same zone as the persistent disk (say us-central1-a), the mounting succeeds. However, if there are in different zones (say node in us-central1-a and disk in us-central1-b) then mounting times out.

Is this behavior valid? I could not find anything in the documentation that verifies that it is.

http://kubernetes.io/docs/user-guide/volumes/#gcePersistentDisk

We are using multi-zone clusters which is making it cumbersome to load the right disk.

Answer 1

GCE Persistent Disks are a zonal resource, so the pod can only request a PD that is in its zone.

Answer 2

You can use this nodeSelector:

    nodeSelector:
      failure-domain.beta.kubernetes.io/zone: us-central1-b

Answer 3

you need to schedule your pods on the same PD zone. In order to do that you need to use nodeSelector or nodeAffinity:required.

If you are using dynamically provisioned volumes, this needs to be topology aware. This is accomplished by setting the volumeBindingMode for the storage class to WaitForFirstConsumer: volume binding