Setting Kubernetes emptyDir volume size

Question

I'm creating a ram based emptyDir volume for a pod.

 volumes:
  - name: ram-disk
    emptyDir:
      medium: "Memory"

Because this is a ram disk, I need to set the maximum size which it will take from the ram. Is there a parameter to set maximum size and minimum size?

Answer 1

Adding an example (extending @flyer' answer):

apiVersion: v1
kind: Pod
...
spec:
  volumes:
    - emptyDir:
        sizeLimit: 1Gi
      name: log

Answer 2

Since Kubernetes 1.20 there is the feature gate SizeMemoryBackedVolumes (currently alpha feature) which does exactly this.

Enable kubelets to determine the size limit for memory-backed volumes (mainly emptyDir volumes).

Answer 3

For kubernetes-1.7.x, it's possible to set the sizeLimit for an EmptyDir.

Answer 4

TL;DR: No, at least not for now.

This is an open issue, see 13479. Since I don't know your use case, I suppose my only suggestion is to try and use hostPath as a workaround, see also the docs for more details.