Update csi-debug.md

Author: andyzhangx

docs/csi-debug.md

@@ -35,13 +35,21 @@ blobfuse 1.2.4
 ```
 
 ### troubleshooting connection failure
+ - blobfuse
 
 Blobfuse mount will fail due to incorrect storage account name, key or container name, run below commands to check whether blobfuse mount would work on agent node:
 ```console
 mkdir test
 export AZURE_STORAGE_ACCOUNT=
 export AZURE_STORAGE_ACCESS_KEY=
 # only for sovereign cloud
-# export AZURE_STORAGE_BLOB_ENDPOINT=<youraccountname>.blob.core.chinacloudapi.cn
+# export AZURE_STORAGE_BLOB_ENDPOINT=accountname.blob.core.chinacloudapi.cn
 blobfuse test --container-name=CONTAINER-NAME --tmp-path=/tmp/blobfuse -o allow_other --file-cache-timeout-in-seconds=120
 ```
+
+ - NFSv3
+ 
+```console
+mkdir /tmp/test
+mount -t nfs -o sec=sys,vers=3,nolock accountname.blob.core.windows.net:/accountname/container-name /tmp/test
+```