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.

The storageClassName is networkvolume if that is what you are referring to — ilegolas, Nov 08 '18 at 04:53
A PV has a type: [link](https://kubernetes.io/docs/concepts/storage/persistent-volumes/#types-of-persistent-volumes). That's what @Rico is asking. — OneK, Nov 08 '18 at 12:53

score 78 · Accepted Answer · edited Sep 11 '22 at 22:47

78

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.

edited Sep 11 '22 at 22:47

Benbob

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answered Nov 09 '18 at 00:51

apisim

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FYI - this does not work if the container does not have the `df` command installed (like many prod containers). Is there another way? – tdensmore Mar 27 '20 at 20:25
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kubectl exec -- df -h – user3008410 Nov 29 '20 at 11:35
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FYI this doesn't work if the pod cannot start due to an error (which might be a full disk) – peetasan Mar 18 '22 at 11:58
Yes, @peetasan. As the answer states: "...If there's a running pod with mounted PV from the PVC..." – apisim Mar 21 '22 at 23:50
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This does not show the used space of the PVC volume claim and instead list the space from the host node – Atif Ali Apr 19 '23 at 10:39

score 28 · Answer 2 · edited Jul 03 '19 at 12:27

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You can monitorize them with kubelet prometheus metrics:

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

edited Jul 03 '19 at 12:27

adiga

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answered Jul 03 '19 at 12:21

Chus

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unfortunately doesn't work with GP3 volumes as of today :/ see https://github.com/kubernetes-sigs/aws-ebs-csi-driver/issues/816 – Tom Sep 10 '21 at 15:10
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'kubelet_volume_stats_used_bytes' see https://stackoverflow.com/a/47117776/1747983 – Tilo Oct 21 '21 at 22:07

Brendan McGrath · Answer 3 · 2021-10-23T00:52:43.293

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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

edited Oct 23 '21 at 00:52

answered May 08 '19 at 05:37

Brendan McGrath

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score 9 · Answer 4 · answered Feb 02 '21 at 11:27

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Adding to @apisim's answer if you add -h parameter then you can get details in human readable format. Something like this,

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

answered Feb 02 '21 at 11:27

nandeesh

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To see pseudo filesystems should be `df -ah` – Sparkler Sep 20 '21 at 21:13

score 0 · Answer 5 · answered Nov 30 '20 at 12:40

If you are using NFS:

sudo apt update
sudo apt install ncdu
cd /your_nfs/kubernetes/
sudo ncdu .

ncdu 1.12 ~ Use the arrow keys to navigate, press ? for help
--- /your_nfs/kubernetes/ ----------------------------------------------------------------------------------
   34.1 GiB [##########] /backups
    2.1 GiB [          ] /redis
    1.9 GiB [          ] /XXX
  785.5 MiB [          ] /postgresql
  435.7 MiB [          ] /XXX
  391.2 MiB [          ] /XXX

Press C to see number/count of files.

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

5 Answers5

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