diff --git a/Hadoop-Compatible-File-System.md b/Hadoop-Compatible-File-System.md
index eab44de..2684e8b 100644
--- a/Hadoop-Compatible-File-System.md
+++ b/Hadoop-Compatible-File-System.md
@@ -160,6 +160,20 @@ If HBase is used, create a folder and configure the HBase root directory in `etc
 ```
 
 # Notes
+## Atomicity
+SeaweedFS satisfies the HCFS [requirements](https://hadoop.apache.org/docs/r2.7.2/hadoop-project-dist/hadoop-common/filesystem/introduction.html) that the following operations to be atomic, when using MySql/Postgres database transactions.
+
+1. Creating a file. If the overwrite parameter is false, the check and creation MUST be atomic.
+1. Deleting a file.
+1. Renaming a file.
+1. Renaming a directory.
+1. Creating a single directory with mkdir().
+
+Among these, except file or directory renaming, the following operations are all atomic for any filer store.
+1. Creating a file
+1. Deleting a file
+1. Creating a single directory with mkdir().
+
 ## No native shared libraries
 The SeaweedFS hadoop client is a pure java library. There are no native libraries to install if you already have Hadoop running.