How to identify the storage space left in a persistent volume claim?

Question

I have a Kubernetes cluster on Google Cloud Platform. It has a persistent Volume Claim with a Capacity of 1GB. The persistent volume claim is bound to many deployments.

I would like to identify the space left in the persistent Volume Claim in order to know if 1GB is sufficient for my application.

I have used the command "kubectl get pv" but this does not show the storage space left.

Answer 1

If there's a running pod with mounted PV from the PVC,

kubectl -n <namespace> exec <pod-name> -- df -ah

...will list all file systems, including the mounted volumes, and their free disk space.

Answer 2

You can monitorize them with kubelet prometheus metrics:

kubelet_volume_stats_available_bytes{persistentvolumeclaim="your-pvc"}
kubelet_volume_stats_capacity_bytes{persistentvolumeclaim="your-pvc"}

Answer 3

I wrote a script that lists all the PVCs in a cluster in a format similar to df.

You can run it via:

./kubedf

or:

./kubedf -h

for a human readable output.

Edit: The script no longer requires kubectl proxy to be running