Google Distributed Cloud (GDC) air-gapped provides block persistent storage for virtual machine (VM) and container workloads in your air-gapped sovereign environment.
GDC uses Kubernetes, which provides persistent
block and file storage through PersistentVolumeClaim
objects. A
PersistentVolumeClaim
(PVC) is a request for storage which is referenced by a
Pod
object. A pod is a group of one or more containers, with shared storage
and network resources. A PersistentVolumeClaim
object has an independent
lifecycle from the pod which allows it to persist beyond a single pod.
Persistent storage is dynamically provisioned, so that the underlying volumes
are created on-demand. In GDC, dynamic provisioning is
provided by the following pre-installed StorageClass
objects:
standard-rwo
:ReadWriteOnce
block storage class. The volume can only be accessed by one node at a time. This storage class features an IOPS guarantee and limit of 3 IOPS per GiB.system-performance-rwo
:ReadWriteOnce
performance block storage class. This storage class is a more performant version of RWO storage that features an IOPS guarantee and limit of 30 IOPS per GiB.
See Create stateful workloads for an example of how to deploy a stateful application with storage.
Before you begin
To run commands against a Kubernetes cluster, ensure you have the following resources:
Locate the Kubernetes cluster name, or ask your Platform Administrator what the cluster name is.
Sign in and generate the kubeconfig file for the Kubernetes cluster if you don't have one.
Use the kubeconfig path of the Kubernetes cluster to replace
KUBERNETES_CLUSTER_KUBECONFIG
in these instructions.
To get the required permissions to create a persistent volume, ask your
Organization IAM Admin to grant you the Namespace Admin role (namespace-admin
)
in your project namespace.
Create a persistent volume
The following instructions show how to create
a volume using the GDC
standard-rwo
StorageClass
.
Create a
PersistentVolumeClaim
and configure it with aReadWriteOnce
access mode and astandard-rwo
storage class:kubectl --kubeconfig KUBERNETES_CLUSTER_KUBECONFIG \ --namespace NAMESPACE apply -f - <<EOF apiVersion: v1 kind: PersistentVolumeClaim metadata: name: PVC_NAME spec: accessModes: - ReadWriteOnce resources: requests: storage: 10Gi storageClassName: standard-rwo EOF
Replace the following:
KUBERNETES_CLUSTER_KUBECONFIG
: the kubeconfig file for the cluster.NAMESPACE
: the project namespace in which to create the PVC.PVC_NAME
: the name of thePersistentVolumeClaim
object.
The
PersistentVolume
(PV) objects are dynamically provisioned. Check the status of the new PVs in your Kubernetes cluster:kubectl get pv --kubeconfig KUBERNETES_CLUSTER_KUBECONFIG
The output is similar to the following:
NAME CAPACITY ACCESS MODES STATUS CLAIM STORAGECLASS AGE pvc-uuidd 10Gi RWO Bound pvc-name standard-rwo 60s
Configure your container workloads to use the PVC. The following is an example
nginx
pod that uses astandard-rwo
PVC:kubectl --kubeconfig KUBERNETES_CLUSTER_KUBECONFIG \ --namespace NAMESPACE apply -f - <<EOF apiVersion: apps/v1 kind: Pod metadata: name: web-server-deployment labels: app: nginx spec: containers: - name: nginx image: nginx volumeMounts: - mountPath: /usr/share/nginx/html name: data volumes: - name: data persistentVolumeClaim: claimName: PVC_NAME EOF
Replace
PVC_NAME
with the PVC you created.
Expand volume capacity
To increase the capacity of a PersistentVolumeClaim
object, update the
spec.resources.storage
field to your desired capacity. The maximum supported
volume size is 14.5 Ti.
Update the volume to a larger size in the manifest file of the
PersistentVolumeClaim
object:kubectl --kubeconfig KUBERNETES_CLUSTER_KUBECONFIG \ --namespace NAMESPACE apply -f - <<EOF apiVersion: v1 kind: PersistentVolumeClaim metadata: name: PVC_NAME spec: accessModes: - ReadWriteOnce resources: requests: storage: VOLUME_STORAGE_SIZE EOF
Replace the following:
KUBERNETES_CLUSTER_KUBECONFIG
: the kubeconfig file for the cluster.NAMESPACE
: the project namespace in which the PVC resource exists.PVC_NAME
: the name of the PVC for which you are increasing the storage size.VOLUME_SNAPSHOT_SIZE
: the storage size amount to increase, such as50Gi
.
Check the status of the updated PVs in your cluster:
kubectl get pv --kubeconfig KUBERNETES_CLUSTER_KUBECONFIG