Merge pull request #282012 from EdB-MSFT/system-assigned-identities-not-supported

added note on sytem-managed identity

Author: prmerger-automator[bot]

articles/azure-monitor/essentials/prometheus-remote-write-virtual-machines.md

@@ -5,7 +5,7 @@ author: EdB-MSFT
 ms.author: edbaynash 
 ms.topic: conceptual
 ms.custom: devx-track-azurecli
-ms.date: 06/20/2024
+ms.date: 07/28/2024
 #customer intent: As an azure administrator, I want to send Prometheus metrics from my self-managed Prometheus instance to an Azure Monitor workspace.
 ---
 
@@ -38,6 +38,9 @@ If you have virtual machines, or a Kubernetes cluster in non-Azure environments,
 
 Onboarding to Azure Arc-enabled services allows you to manage and configure non-Azure virtual machines in Azure. Once onboarded, configure [Remote-write using user-assigned managed identity](#remote-write-using-user-assigned-managed-identity-authentication) authentication. For more Information on onboarding Virtual Machines to Azure Arc-enabled servers, see [Azure Arc-enabled servers](/azure/azure-arc/servers/overview) and [Azure Arc-enabled Kubernetes](/azure/azure-arc/kubernetes/overview).
 
+> [!NOTE]
+> System-assigned managed identity is not supported for remote-write to Azure Monitor workspaces. Use user-assigned managed identity or Microsoft Entra ID application authentication.
+
 
 ## Prerequisites
 
@@ -123,7 +126,7 @@ For each Virtual Machine Scale Set in the resource group, assign the managed ide
 ### [Microsoft Entra ID application](#tab/entra-application)
 ### Remote-write using Microsoft Entra ID application authentication
 
-Microsoft Entra ID application authentication can be used in any environment. If your Prometheus service is running in an Azure-managed environment consider using user-assigned managed identity authentication.
+Microsoft Entra ID application authentication can be used in any environment. If your Prometheus service is running in an Azure-managed environment, consider using user-assigned managed identity authentication.
 
 To configure remote-write to Azure Monitor workspace using a Microsoft Entra ID application, create an Entra application. On Azure Monitor workspace's data collection rule, assign the `Monitoring Metrics Publisher` role to the Entra application.