use weed shell commands fs.meta.save/load/notify

Async-Replication-to-another-Filer.md

@@ -59,4 +59,4 @@ Please read the source.filer and sink.filer configurations carefully and make su
 
 The `weed filer.replicate` only replicates files that have been updated. If there are already a lot of files, very likely you would need to copy them too.
 
-To do this, use `weed filer.export -targetStore=notification`, which will iterate all files and generate one "file creation" event for each file to the message queue. Thus, all files will be replicated.
+To do this, use `echo 'fs.meta.notify' | weed shell`, which will iterate all files and generate one "file creation" event for each file to the message queue. Thus, all files will be replicated.

Directories-and-Files.md

@@ -86,11 +86,28 @@ The Filer Store persists all file metadata and directory information.
 | Postgres     | O(logN)| unlimited | Local or Distributed, Fast     |Atomic| | Easy to manage, export |
 
 #### Switching between different Stores
-It is easy to switch between different filer stores (except memory store).
+It is easy to switch between different filer stores.
 
 For example:
 ```sh
-weed filer.export -sourceStore=mysql -targetStore=cassandra
+
+# first save current filer meta data
+
+$ weed shell
+> fs.cd   http://filerHost:filerPort/
+> fs.meta.save
+...
+total 65 directories, 292 files
+meta data for http://localhost:8888/ is saved to localhost-8888-20190417-005421.meta
+> exit
+
+# now switch to a new filer, and load the previously saved metadata
+$ weed shell
+> fs.meta.load localhost-8888-20190417-005421.meta
+...
+total 65 directories, 292 files
+localhost-8888-20190417-005421.meta is loaded to http://localhost:8888/
+
 ```
 
 ### Extending Storage Options

Migrate-to-Filer-Store.md

@@ -2,7 +2,7 @@ If there are already a lot of files, how to move them to the SeaweedFS the most
 
 ### 1. Setup Filer
 1. create a filer.toml file, see the output of "weed scaffold -config=filer"
-1. choose and setup a filer data store. It is OK to just pick one and use it. You can always switch later. For example: `weed filer.export -sourceStore=mysql -targetStroe=cassandra`
+1. choose and setup a filer data store. It is OK to just pick one and use it. You can always switch later.
 3. start the filer
 > Example: `weed filer -master=localhost:9333`