Update README.md

Author: andyzhangx

README.md

@@ -38,6 +38,8 @@ Please refer to `blob.csi.azure.com` [driver parameters](./docs/driver-parameter
 This option does not depend on cloud provider config file, supports cross subscription and on-premise cluster scenario. Refer to [detailed steps](./deploy/example/e2e_usage.md#option2-bring-your-own-storage-account).
 
 ### Install driver on a Kubernetes cluster
+> Note: this only works on Ubuntu 18.04 node now
+>
 > To install specific blobfuse v1 version, run following command directly after driver is running on the agent node:
 > ```console
 > kubectl patch daemonset csi-blob-node -n kube-system -p '{"spec":{"template":{"spec":{"initContainers":[{"env":[{"name":"INSTALL_BLOBFUSE","value":"true"},{"name":"BLOBFUSE_VERSION","value":"1.4.5"}],"name":"install-blobfuse-proxy"}]}}}}'