Updated Mount Remote Storage (markdown)

Mount-Remote-Storage.md

@@ -27,6 +27,22 @@ This operation will pull down all metadata from the remote storage.
 
 Later, any metadata operations can be invoked locally, and respond very fast.
 
+## Write Back changes to Remote Storage
+
+If the mounted directory is only for reading, you can start to use it.
+
+If you want to change files in the mounted directory, a separate process `weed filer.remote.sync -dir=xxx` should be started.
+This process will listen to filer change events, and write any changes back to the remote storage.
+
+```
+weed filer.remote.sync -filer=<filerHost>:<filerPort> -dir=xxx
+```
+
+## Unmount a Remote Storage
+
+Similarly, running `remote.unmount -dir=xxx` can unmount a remote storage. However, this means all cached data and metadata will be lost.
+And if `weed filer.remote.sync -filer=<filerHost>:<filerPort> -dir=xxx` was not run, the updated local data have not been uploaded to the remote storage, so these local changes will be lost.
+
 ## Benefits to Cache Metadata
 
 ### Speed up meta data operations