diff --git a/Cloud-Tier.md b/Cloud-Tier.md
index d39986b..1be9314 100644
--- a/Cloud-Tier.md
+++ b/Cloud-Tier.md
@@ -19,9 +19,13 @@ If one volume is tiered to the cloud,
 ## Usage
 1. Use `weed scaffold -conf=master` to generate `master.toml`, tweak it, and start master server with the `master.toml`.
 1. Use `volume.tier.upload` in `weed shell` to move volumes to the cloud.
+1. Use `volume.tier.download` in `weed shell` to move volumes to the local cluster.
 
 ## Configuring Storage Backend
 (Currently only s3 is developed. More is coming soon.)
+
+Multiple s3 buckets are supported. Usually you just need to configure one backend.
+
 ```
 [storage.backend]
 	[storage.backend.s3.default]
@@ -30,22 +34,28 @@ If one volume is tiered to the cloud,
 	aws_secret_access_key = ""     # if empty, loads from the shared credentials file (~/.aws/credentials).
 	region = "us-west-1"
 	bucket = "one_bucket"          # an existing bucket
+
+	[storage.backend.s3.name2]
+	enabled = true
+	aws_access_key_id     = ""     # if empty, loads from the shared credentials file (~/.aws/credentials).
+	aws_secret_access_key = ""     # if empty, loads from the shared credentials file (~/.aws/credentials).
+	region = "us-west-2"
+	bucket = "one_bucket_two"          # an existing bucket
+
 ```
 
-After this is configured, you can use this command.
+After this is configured, you can use this command to upload the .dat file content to the cloud.
 
 ```
 // move the volume 37.dat to the s3 cloud
 volume.tier.upload -dest=s3 -collection=benchmark -volumeId=37
 // or
 volume.tier.upload -dest=s3.default -collection=benchmark -volumeId=37
+// if for any reason you want to move the volume to a different bucket
+volume.tier.upload -dest=s3.name2 -collection=benchmark -volumeId=37
 
 ```
 
 
-## Data Layout
-The dat file on the cloud will be laid out following best practices. Especially, the name is a randomized UUID to ensure the dat file can be spread out evenly.
-
-