Merge pull request #290231 from huguesBouvier/patch-1

Update howto-disk-backed-message-buffer.md

Author: ShannonLeavitt

articles/iot-operations/manage-mqtt-broker/howto-disk-backed-message-buffer.md

@@ -27,7 +27,10 @@ The **disk-backed message buffer** feature is used for efficient management of m
 <!-- TODO: accuracy check -->
 By default, the disk-backed message buffer feature is disabled. In this case, messages remain in memory, and back pressure is applied to clients as the reader pool or scratch pool reaches the limit as defined by the [subscriber queue limit](./howto-broker-mqtt-client-options.md#subscriber-queue-limit). 
 
-Understanding and configuring the disk-backed message buffer feature maintains a robust and reliable message queuing system. Proper configuration is important in scenarios where message processing speed and connectivity are critical factors.
+Configuring the disk-backed message buffer is essential for maintaining a robust and reliable message queuing system, especially in scenarios where message processing speed and connectivity are critical.
+
+> [!NOTE]
+> The MQTT broker writes data to disk exactly as received from clients, without additional encryption. Securing the disk is essential to protect the data stored by the broker.
 
 ## Configuration options