I try to use a persistent volume for my rethinkdb server. But I got this error:
Unable to mount volumes for pod "rethinkdb-server-deployment-6866f5b459-25fjb_default(efd90244-7d02-11e8-bffa-42010a8400b9)": timeout expired waiting for volumes to attach/mount for pod "default"/"rethinkdb-server-deployment-
Multi-Attach error for volume "pvc-f115c85e-7c42-11e8-bffa-42010a8400b9" Volume is already used by pod(s) rethinkdb-server-deployment-58f68c8464-4hn9xI think that Kubernetes deploy a new node without removed the old one so it can't share le volume between both because my pvc is ReadWriteOnce. This persistent volume must be create in an automatic way, so I can't use persistent disk, format it ...
My configuration:
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
namespace: default
name: rethinkdb-pvc
spec:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 30Gi
apiVersion: apps/v1beta1
kind: Deployment
metadata:
namespace: default
labels:
db: rethinkdb
role: admin
name: rethinkdb-server-deployment
spec:
replicas: 1
selector:
matchLabels:
app: rethinkdb-server
template:
metadata:
name: rethinkdb-server-pod
labels:
app: rethinkdb-server
spec:
containers:
- name: rethinkdb-server
image: gcr.io/$PROJECT_ID/rethinkdb-server:$LAST_VERSION
env:
- name: POD_NAMESPACE
valueFrom:
fieldRef:
fieldPath: metadata.namespace
ports:
- containerPort: 8080
name: admin-port
- containerPort: 28015
name: driver-port
- containerPort: 29015
name: cluster-port
volumeMounts:
- mountPath: /data/rethinkdb_data
name: rethinkdb-storage
volumes:
- name: rethinkdb-storage
persistentVolumeClaim:
claimName: rethinkdb-pvcHow do you manage this?
I see that you’ve added the PersistentVolumeClaim within a deployment. I also see that you are trying to scale the node pool.
A PersistentVolumeClaim will work on a deployment, but only if you are not scaling the deployment. This is why that error message showed up. The error that you are seeing says that that volume is already in use by an existing pod when a new pod is replicated.
Because you are trying to scale the deployment, other replicas will try to mount and use the same volume.
Solution: Deploy the PersistentVolumeClaim in a statefulset object, not a deployment. Instructions on how to deploy a statefulset can be found in this article. With a statefulset, you will be able to attach a PersistentVolumeClaim to a pod, then scale the node pool.