Merge pull request #26818 from andyzhangx/azurefile-migration-dev1.21

Update Azure file feature gates for 1.21 beta

content/en/docs/concepts/storage/volumes.md

@@ -152,14 +152,16 @@ For more details, see the [`azureFile` volume plugin](https://github.com/kuberne
 
 #### azureFile CSI migration
 
-{{< feature-state for_k8s_version="v1.15" state="alpha" >}}
+{{< feature-state for_k8s_version="v1.21" state="beta" >}}
 
 The `CSIMigration` feature for `azureFile`, when enabled, redirects all plugin operations
 from the existing in-tree plugin to the `file.csi.azure.com` Container
 Storage Interface (CSI) Driver. In order to use this feature, the [Azure File CSI
 Driver](https://github.com/kubernetes-sigs/azurefile-csi-driver)
 must be installed on the cluster and the `CSIMigration` and `CSIMigrationAzureFile`
-alpha features must be enabled.
+[feature gates](/docs/reference/command-line-tools-reference/feature-gates/) must be enabled.
+
+Azure File CSI driver does not support using same volume with different fsgroups, if Azurefile CSI migration is enabled, using same volume with different fsgroups won't be supported at all.
 
 ### cephfs
 

content/en/docs/reference/command-line-tools-reference/feature-gates.md

@@ -72,7 +72,8 @@ different Kubernetes components.
 | `CSIMigrationAzureDisk` | `false` | Alpha | 1.15 | 1.18 |
 | `CSIMigrationAzureDisk` | `false` | Beta | 1.19 | |
 | `CSIMigrationAzureDiskComplete` | `false` | Alpha | 1.17 | |
-| `CSIMigrationAzureFile` | `false` | Alpha | 1.15 | |
+| `CSIMigrationAzureFile` | `false` | Alpha | 1.15 | 1.19 |
+| `CSIMigrationAzureFile` | `false` | Beta | 1.21 | |
 | `CSIMigrationAzureFileComplete` | `false` | Alpha | 1.17 | |
 | `CSIMigrationGCE` | `false` | Alpha | 1.14 | 1.16 |
 | `CSIMigrationGCE` | `false` | Beta | 1.17 | |