Merge pull request #115906 from dcurwin/vm-subscription-backup-may2020

VMs must be in the same region and subscription as the vault

Author: PRMerger16

articles/backup/backup-azure-arm-vms-prepare.md

@@ -103,6 +103,9 @@ Configure a backup policy for the vault.
 
      !["Select virtual machines" pane](./media/backup-azure-arm-vms-prepare/select-vms-to-backup.png)
 
+    >[!NOTE]
+    > Only VMs in the same region and subscription as that of the vault will be available to configure backup.
+
 5. In **Backup**, click **Enable backup**. This deploys the policy to the vault and to the VMs, and installs the backup extension on the VM agent running on the Azure VM.
 
      !["Enable backup" button](./media/backup-azure-arm-vms-prepare/vm-validated-click-enable.png)

articles/backup/backup-support-matrix-iaas.md

@@ -43,7 +43,7 @@ Back up disks after migrating to managed disks | Supported.<br/><br/> Backup wil
 Back up managed disks after enabling resource group lock | Not supported.<br/><br/> Azure Backup can't delete the older restore points, and backups will start to fail when the maximum limit of restore points is reached.
 Modify backup policy for a VM | Supported.<br/><br/> The VM will be backed up by using the schedule and retention settings in new policy. If retention settings are extended, existing recovery points are marked and kept. If they're reduced, existing recovery points will be pruned in the next cleanup job and eventually deleted.
 Cancel a backup job| Supported during snapshot process.<br/><br/> Not supported when the snapshot is being transferred to the vault.
-Back up the VM to a different region or subscription |Not supported.
+Back up the VM to a different region or subscription |Not supported.<br><br>To successfully back up, virtual machines must be in the same subscription as the vault for backup.
 Backups per day (via the Azure VM extension) | One scheduled backup per day.<br/><br/>The  Azure Backup service supports up to nine on-demand backups per day, but Microsoft recommends no more than four daily on-demand backups to ensure best performance.
 Backups per day (via the MARS agent) | Three scheduled backups per day.
 Backups per day (via DPM/MABS) | Two scheduled backups per day.