adding instrux for snapshot mount

Author: khdownie

articles/storage/files/media/storage-how-to-use-files-linux/mount-snapshot.png

@@ -4,7 +4,7 @@ description: Learn how to mount an Azure file share over SMB on Linux and review
 author: khdownie
 ms.service: storage
 ms.topic: how-to
-ms.date: 11/03/2022
+ms.date: 01/04/2023
 ms.author: kendownie
 ms.subservice: files
 ---
@@ -184,7 +184,7 @@ mntRoot="/mount"
 sudo mkdir -p $mntRoot
 ```
 
-To mount an Azure file share on Linux, use the storage account name as the username of the file share, and the storage account key as the password. Since the storage account credentials may change over time, you should store the credentials for the storage account separately from the mount configuration. 
+To mount an Azure file share on Linux, use the storage account name as the username of the file share, and the storage account key as the password. Because the storage account credentials may change over time, you should store the credentials for the storage account separately from the mount configuration. 
 
 The following example shows how to create a file to store the credentials. Remember to replace `<resource-group-name>` and `<storage-account-name>` with the appropriate information for your environment.
 
@@ -302,6 +302,29 @@ The final step is to restart the `autofs` service.
 sudo systemctl restart autofs
 ```
 
+## Mount a file share snapshot
+
+If you want to mount a specific snapshot of an SMB Azure file share, you must supply the `snapshot` option as part of the `mount` command, where `snapshot` is the time that the particular snapshot was created in GMT format such as @GMT-2022.12.12-09.52.43. The `snapshot` option has been supported in the Linux kernel since version 4.19.
+
+After you've created the file share snapshot, following these instructions to mount it.
+
+1. In the Azure portal, navigate to the storage account that contains the file share that you want to mount a snapshot of.
+2. Select **Data storage > File shares** and select the file share.
+3. Select **Operations > Snapshots** and take note of the name of the snapshot you want to mount. The snapshot name will be a timestamp, such as in the screenshot below.
+
+:::image type="content" source="media/storage-how-to-use-files-linux/mount-snapshot.png" alt-text="Screenshot showing how to locate a file share snapshot name and timestamp in the Azure portal." border="true" :::
+
+4. Convert the timestamp to the GMT format expected by the `mount` command.
+5. Run the `mount` command using the GMT time to specify the `snapshot` value. Be sure to replace `<storage-account-name>` and `<file-share-name>` with your values. The .cred file contains the credentials to be used to mount the share (see [Automatically mount file shares](#automatically-mount-file-shares)).
+
+```bash
+sudo mount -t cifs //<storage-account-name>.file.core.windows.net/<file-share-name> /mnt/<file-share-name>/snapshot1 -o credentials=/etc/smbcredentials/snapshottestlinux.cred,[email protected]
+```
+
+6. If you're able to browse the snapshot under the path /mnt/snapshot-test-share1/snapshot1, then the mount succeeded. 
+
+If the mount fails, see Troubleshooting.
+
 ## Next steps
 See these links for more information about Azure Files: