Update sql-server-linux-backup-and-restore-database.md

VanMSFT · web-flow · commit 514ce2a750bb · 2020-10-05T11:50:03.000-07:00
diff --git a/docs/linux/sql-server-linux-backup-and-restore-database.md b/docs/linux/sql-server-linux-backup-and-restore-database.md
@@ -16,6 +16,9 @@ ms.assetid: d30090fb-889f-466e-b793-5f284fccc4e6
 
 You can take backups of databases from SQL Server 2017 on Linux with many different options. On a Linux server, you can use **sqlcmd** to connect to the SQL Server and take backups. From Windows, you can connect to SQL Server on Linux and take backups with the user interface. The backup functionality is the same across platforms. For example, you can backup databases locally, to remote drives, or to [Microsoft Azure Blob storage service](../relational-databases/backup-restore/sql-server-backup-to-url.md).
 
+> [!IMPORTANT]
+> SQL Server on Linux only supports backing up to Azure Blob storage using block blobs. Using a storage key for backup and restore will result in a page blog being used, which isn't supported. Use a Shared Access Signature instead. For information on block blogs versus page blogs, see [Backup to block blob vs. page blob](../relational-databases/backup-restore/sql-server-backup-to-url.md#blockbloborpageblob).
+
 ## Backup a database
 
 In the following example **sqlcmd** connects to the local SQL Server instance and takes a full backup of a user database called `demodb`.
