Merge pull request #236021 from MikeRayMSFT/20230426-backup-controller-database

Stage backup controller database.

Author: v-regandowner

articles/azure-arc/data/backup-controller-database.md

@@ -0,0 +1,66 @@
+---
+title: Backup controller database
+description: Explains how to backup the controller database for Azure Arc-enabled data services
+services: azure-arc
+ms.service: azure-arc
+ms.subservice: azure-arc-data
+author: dnethi
+ms.author: dinethi
+ms.reviewer: mikeray
+ms.date: 04/26/2023
+ms.topic: how-to
+---
+
+# Backup controller database 
+
+When you deploy Azure Arc data services, the Azure Arc Data Controller is one of the most critical components of the deployment. The data controller:
+
+- Provisions and deprovisions resources
+- Orchestrates most of the activities for Azure Arc-enabled SQL Managed Instance
+- Captures the billing and usage information of each Arc SQL managed instance. 
+
+All information such as inventory of all the Arc SQL managed instances, billing, usage and the current state of all these SQL managed instances is stored in a database called `controller` under the SQL Server instance that is deployed into the `controldb-0` pod. 
+
+This article explains how to back up the controller database.
+
+Following steps are needed in order to back up the `controller` database:
+
+1. Retrieve the credentials for the secret
+1. Decode the base64 encoded credentials
+1. Use the decoded credentials to connect to the SQL instance hosting the controller database, and issue the `BACKUP` command
+
+## Retrieve the credentials for the secret
+
+`controller-db-rw-secret` is the secret that holds the credentials for the `controldb-rw-user` user account that can be used to connect to the SQL instance. 
+Run the following command to retrieve the secret contents:
+
+```azurecli
+kubectl get secret controller-db-rw-secret --namespace [namespace] -o yaml
+```
+
+For example:
+
+```azurecli
+kubectl get secret controller-db-rw-secret --namespace arcdataservices -o yaml
+```
+
+## Decode the base64 encoded credentials
+
+The contents of the yaml file of the secret `controller-db-rw-secret` contain a `password` and `username`. You can use any base64 decoder tool to decode the contents of the `password`.
+
+## Back up the database
+
+With the decoded credentials, run the following command to issue a T-SQL `BACKUP` command to back up the controller database.
+
+```azurecli
+kubectl exec controldb-0 -n contosons -c  mssql-server -- /opt/mssql-tools/bin/sqlcmd -S localhost -U controldb-rw-user -P "<password>" -Q "BACKUP DATABASE [controller] TO  DISK = N'/var/opt/controller.bak' WITH NOFORMAT, NOINIT,  NAME = N'Controldb-Full Database Backup', SKIP, NOREWIND, NOUNLOAD,  STATS = 10, CHECKSUM"
+```
+
+Once the backup is created, you can move the `controller.bak` file to a remote storage for any recovery purposes. 
+
+> [!TIP]
+> Back up the controller database before and after any custom resource changes such as creating or deleting an Arc-enabled SQL Managed Instance.
+
+## Next steps
+
+[Azure Data Studio dashboards](azure-data-studio-dashboards.md)

articles/azure-arc/data/toc.yml

@@ -76,6 +76,8 @@ items:
           href: view-billing-data-in-azure.md
         - name: View data controller (portal)
           href: view-data-controller-in-azure-portal.md
+        - name: Backup data controller
+          href: backup-controller-database.md
         - name: Delete resources
           href: delete-azure-resources.md
         - name: Uninstall Azure Arc data controller