emptyDir volume with medium Memory prevents scale down

[coryflucas]

Pods with local storage are supposed to prevent scale down, but it appears that emptyDir volumes with medium set to Memory also count. Is this intentional? Given the doc warn that these volumes are backed by tmpfs and will be lost on Node reboot, it seems like these should be considered safe to remove.

I'd be happy to submit a PR if this would be an acceptable change.

[futurekill]

+1

[kevinsimper]

I was surprised by the same, the idea of giving a pod a tmpfs would in my mind make it safe to evict.

The line that checks it is right here:
https://github.com/kubernetes/autoscaler/blob/master/cluster-autoscaler/utils/drain/drain.go#L244

and is started here:
https://github.com/kubernetes/autoscaler/blob/master/cluster-autoscaler/utils/drain/drain.go#L197

But you can set the pods annotation (not on the deployment) to this:
"cluster-autoscaler.kubernetes.io/safe-to-evict": "true"

[aleksandra-malinowska]

It's intentional. safe-to-evict annotation mentioned above is the recommended workaround.