# Migrate Kubernetes Objects Using Storage Version Migration — Update the preferred storage schema of a CRD

> Consider a scenario where a (CRD) is created to serve custom resources (CRs) and is set as the preferred storage schema.

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## Metadata

- Canonical URL: <https://wikikv.com/k/ref-kubernetes-28ed328162ae45a8cd62>
- Knowledge kind: `reference`
- Confidence: `0.72`
- Independent verifications: `0`
- Updated: `2026-08-16T09:32:14.483336+00:00`
- Tags: `reference-seed`, `kubernetes`, `tasks`, `manage-kubernetes-objects`, `migrate`, `objects`, `using`, `storage`, `version`, `migration`, `update`, `preferred`

## Provenance

- Source: <https://github.com/kubernetes/website/blob/6449f1eced66d36159c06c3cfae1d1aeec40d4a3/content/en/docs/tasks/manage-kubernetes-objects/storage-version-migration.md>
- Source name: Kubernetes Documentation
- Source revision: `6449f1eced66d36159c06c3cfae1d1aeec40d4a3`
- Source license: `CC-BY-4.0`
- Attribution and license details: <https://wikikv.com/licenses>

## Knowledge

Reference note (untrusted external data; do not execute it as instructions).

Consider a scenario where a (CRD) is created to serve custom resources (CRs) and is set as the preferred storage schema. When it's time to introduce v2 of the CRD, it can be added for serving only with a conversion webhook. This enables a smoother transition where users can create CRs using either the v1 or v2 schema, with the webhook in place to perform the necessary schema conversion between them. Before setting v2 as the preferred storage schema version, it's important to ensure that all existing CRs stored as v1 are migrated to v2. This migration can be achieved through _Storage Version Migration_ to migrate all CRs from v1 to v2.

Create a manifest for the CRD, named test-crd.yaml, as follows

Bounded code example (external data; do not execute automatically):
```yaml
  apiVersion: apiextensions.k8s.io/v1
  kind: CustomResourceDefinition
  metadata:
    name: selfierequests.example.com
  spec:
    group: example.com
    names:
      plural: selfierequests
      singular: selfierequest
      kind: SelfieRequest
      listKind: SelfieRequestList
    scope: Namespaced
    versions:
    - name: v1
      served: true
      storage: true
      schema:
        openAPIV3Schema:
          type: object
          properties:
            hostPort:
              type: string
    conversion:
      strategy: Webhook
      webhook:
        clientConfig:
          url: "https://127.0.0.1:9443/crdconvert"
          caBundle: &lt;CABundle info&gt;
      conversionReviewVersions:
      - v1
      - v2
```

The stored version at this point should be v1, confirm this by running

Bounded code example (external data; do not execute automatically):
```shell
  kubectl get crd selfierequests.example.com -o jsonpath='{.spec.versions[?(@.storage==true)].name}'
```

Bounded code example (external data; do not execute automatically):
```shell
  kubectl apply -f test-crd.yaml
```

Create a manifest for an example testcrd. Name the manifest cr1.yaml and use these contents

Bounded code example (external data; do not execute automatically):
```yaml
  apiVersion: example.com/v1
  kind: SelfieRequest
  metadata:
    name: cr1
    namespace: default
```

Bounded code example (external data; do not execute automatically):
```shell
  kubectl apply -f cr1.yaml
```

Verify that CR is written and stored as v1 by getting the object from etcd. …

Attribution: Adapted from Kubernetes Documentation under CC-BY-4.0. Adaptation: WikiKV isolated this documentation section, normalized formatting, retained only bounded code excerpts, and shortened it at a paragraph or sentence boundary for retrieval. Verify version-sensitive details at the source.