Practical guide

Kubernetes Ephemeral Storage: Requests, Limits, and Node Capacity

Learn what Kubernetes ephemeral storage includes, estimate pod requests and limits, and avoid confusing it with persistent volume capacity.

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Kubernetes ephemeral storage is the node-local space used by container writable layers, logs, and emptyDir volumes. It is different from persistent volume capacity and should be planned separately.

Quick answer

Multiply the number of replicas by the per-pod request to estimate scheduled ephemeral-storage capacity. Multiply by the per-pod limit to estimate the maximum configured allowance. The Kubernetes ephemeral storage calculator performs both conversions in GiB and MiB.

For example, six pods requesting 2 GiB each need 12 GiB of requested ephemeral storage. A 4 GiB limit per pod creates a 24 GiB aggregate limit.

What the estimate leaves out

The arithmetic does not prove that a node can safely host the workload. Compare the result with node allocatable ephemeral storage, kubelet eviction thresholds, image-layer usage, system logs, and DaemonSets. A pod can also be evicted when the node is under disk pressure even when its configured limit has not been reached.

Use the result as a capacity-planning input, then verify it against observed disk usage and the node’s eviction behavior.

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