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Scan for outdated or missing drivers - takes under a minuteDriver Scan →Clear out junk files and repair common Windows errorsFree Scan →Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →Use a persistent volume claim (PVC) backed by a PersistentVolume (PV) when data must survive Pod deletion. Choose an ephemeral volume when data is disposable, rebuildable, or tied to one Pod—such as scratch files, caches, logs, or configuration inputs. The key distinction is not simply “persistent or temporary”: Kubernetes has several ephemeral volume types with different provisioning, scheduling, and cleanup behavior.
How to choose between persistent and ephemeral storage
Start with the data’s lifecycle, then check failure tolerance, provisioning, capacity controls, and cleanup. A container’s writable filesystem is not durable application storage: its writable state is not saved when the container stops, whereas a volume can preserve data across container restarts. A volume’s persistence and availability still depend on its type and storage backend. See the Kubernetes documentation on Volumes.
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| Question | Choose persistent storage when… | Choose ephemeral storage when… |
|---|---|---|
| Must the data survive Pod deletion? | Yes. Use a PVC/PV and plan the claim and reclaim lifecycle. | No. The data may be removed with the Pod or its node. |
| What kind of data is it? | Application state or other data that must remain available independently of one Pod. | Scratch files, rebuildable caches, logs, or injected configuration and secrets. |
| What happens if a node fails? | Check the storage backend’s failure domain and recovery behavior; a PV alone does not guarantee availability. | Local ephemeral data may be lost if its node fails. |
| How is storage provisioned? | A PVC requests storage from an existing PV or through a StorageClass. | Depending on the type, kubelet provides local storage, a CSI driver supplies an inline volume, or Kubernetes creates a Pod-owned PVC. |
| What governs cleanup? | The PV reclaim policy and backend determine what happens after a claim is released. | The specific ephemeral type determines its lifecycle; generic ephemeral volumes normally follow the Pod’s lifecycle. |
For a choice between particular CSI drivers or cloud storage offerings, compare their documented performance, backup, snapshot, expansion, and availability behavior. Those properties cannot be inferred from the Kubernetes volume category alone.
What persistent volumes do—and do not—guarantee
A PV represents cluster storage provisioned by an administrator or dynamically through a StorageClass. A workload requests it through a PVC. The storage is not destroyed merely because an individual Pod ceases to exist, so a claim can support data that must outlive a Pod.
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“Persistent” does not mean undeletable, backed up, or highly available. Once a claim is released, the PV’s reclaim policy governs what Kubernetes does with the underlying asset. Dynamically created volumes use the StorageClass reclaim policy; if the class does not specify one, the documented default is Delete. With Retain, the asset remains for separate recovery or cleanup. Check the Kubernetes documentation for Persistent Volumes and Storage Classes.
For important application state, make the claim lifecycle explicit and align the reclaim policy with your recovery plan. Confirm the backend’s failure domain, backup process, and any application consistency requirements: PV/PVC lifecycle behavior by itself establishes none of those guarantees.
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Ephemeral volume types are not interchangeable
Kubernetes documents emptyDir, projected configMap, downwardAPI, and secret volumes, image volumes, CSI ephemeral volumes, and generic ephemeral volumes. The first group commonly supplies local ephemeral data managed by kubelet; CSI and generic ephemeral volumes involve storage drivers in different ways. CSI ephemeral volumes have been stable since Kubernetes v1.25, and generic ephemeral volumes since v1.23. These are feature-stability milestones, not performance comparisons. See Ephemeral Volumes.
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1Repair Windows errors before they cause bigger problems2Scan for outdated or missing drivers - takes under a minute3Clear out junk files and repair common Windows errorsemptyDir for Pod-scoped scratch space
An emptyDir starts empty for the Pod and can provide scratch space on local disk or in memory. It fits temporary working files and rebuildable caches. Local ephemeral storage also includes kubelet-managed data such as logs and writable container layers. It has no long-term durability guarantee and can be lost if the node fails. A memory-backed emptyDir uses tmpfs, and Kubernetes accounts that memory as container memory rather than local ephemeral storage.
ConfigMap, Secret, and other projected inputs
Use the matching projected volume for configuration, secrets, or Pod metadata rather than treating those inputs as application state. These volumes serve as inputs to a workload; they are not a substitute for durable storage of data the application creates.
Generic ephemeral volumes for Pod-owned claims
A generic ephemeral volume puts a claim template in the Pod specification. Kubernetes creates a PVC in the Pod’s namespace and makes the Pod its owner. It can use local or network-attached storage and driver-supported capabilities such as sizing, initial data, snapshots, cloning, resizing, and storage-capacity tracking.
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Deleting the Pod normally deletes its PVC; the fate of the provisioned volume then depends on the reclaim policy. Under the default Delete policy, the volume is often deleted as well. Retain changes that cleanup behavior. Because a generic ephemeral volume creates a PVC, account for it in namespace quotas and admission policy. PVC names are constructed from the Pod and volume names; a collision with another Pod’s naming combination or a manually created PVC can prevent the Pod from starting, although Kubernetes detects ownership conflicts.
CSI ephemeral volumes for driver-provided inline storage
A CSI ephemeral volume is specified inline in the Pod and is created after the Pod is scheduled. Only some CSI drivers support this mode, and it does not support storage-capacity-aware scheduling. Check the selected driver’s documentation for its attributes and limitations, and ensure inline use does not expose configuration that administrators intend to restrict.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Control local ephemeral storage consumption
Kubernetes can track, reserve, and limit local ephemeral storage with ephemeral-storage requests and limits. An emptyDir.sizeLimit can set a volume-specific cap. Accounting may cover non-tmpfs emptyDir data, logs, and writable layers when the node uses a supported filesystem layout. If kubelet cannot measure the relevant storage, configured limits may not be enforced as expected; verify the node’s filesystem configuration. For details, see Local ephemeral storage.
Local persistent volumes have a placement constraint
A local PV is tied to storage on a particular node, so it needs node affinity to place its Pod on the correct node. The volume can become inaccessible when that node is unhealthy. For local volumes, the Kubernetes documentation recommends delayed binding with WaitForFirstConsumer, allowing the scheduler to consider the Pod’s constraints when selecting the volume. See Storage Classes.
A practical decision path
- Data may be discarded or rebuilt with the Pod: choose an appropriate ephemeral type. For node-local scratch data, consider
emptyDirand configure storage requests, limits, or a size limit where supported. - The Pod needs configuration, a secret, or metadata: use the corresponding projected Kubernetes volume, not application-state storage.
- Each Pod needs provisioned storage that should be cleaned up with it: consider a generic ephemeral volume, then confirm the StorageClass reclaim policy, driver features, quotas, and naming constraints.
- You need an inline CSI volume: verify that the driver supports CSI ephemeral lifecycle mode and account for the lack of capacity-aware scheduling.
- Data must outlive a Pod: use a PVC/PV, select reclaim behavior deliberately, and confirm backup and recovery arrangements with the storage provider or cluster administrator.
Kubernetes documents the lifecycle and configuration mechanisms, but the right provider-specific choice depends on the StorageClasses and CSI drivers installed in your cluster, as well as the workload’s performance and recovery requirements.
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