quick-start-with-dm: add selinux note

dm/quick-start-with-dm.md

@@ -8,6 +8,10 @@ aliases: ['/docs/tidb-data-migration/dev/get-started/']
 
 This document describes how to migrate data from MySQL to TiDB using [TiDB Data Migration (DM)](/dm/dm-overview.md). This guide is a quick demo of DM features and is not recommended for any production environment.
 
+> **Note:**
+>
+> If your target machine's operating system supports SELinux, make sure that SELinux is **disabled**.
+
 ## Step 1: Deploy a DM cluster
 
 1. Install TiUP, and install [`dmctl`](/dm/dmctl-introduction.md) using TiUP: