# Keep the MABS SQL instance local when planning an Azure Stack Hub installation

> Can an Azure Stack Hub MABS installation use a shared remote SQL Server instance?

- Canonical URL: https://update.dsesecurity.com/updates/dse-20260909-527-keep-the-mabs-sql-instance-local-when-planning-an-azure-stack-hub-installation/
- Publisher: Detection Systems & Engineering (DSE Security)
- Author: DSE Security Editorial Team
- Published: 2026-09-10T00:23:09+00:00
- Modified: 2026-09-10T02:11:18+00:00
- Last reviewed by DSE: 2026-09-09
- Resource type: Guide
- DSE priority: Information
- Topics: Business Continuity, IT
- Reading time: 2 minutes

## What you need to know

Can an Azure Stack Hub MABS installation use a shared remote SQL Server instance?

## Potentially affected

Apply this placement review to Microsoft Azure Backup Server on Azure Stack Hub. Validate the chosen operating system, MABS release and SQL combination against the current requirements; the installation page's older sizing examples are not a general capacity recommendation.

## DSE recommendation

Reject a shared remote-database design before starting installation.

## Article

## Source facts

Microsoft’s Azure Stack Hub installation guidance requires the SQL Server instance used by Azure Backup Server to be local; a remote instance is not supported. The backup server is intended for a dedicated, single-purpose virtual machine. The same guidance excludes installation on a domain controller, an Exchange server, an Application Server-role machine or a cluster node. [Microsoft Learn](https://learn.microsoft.com/en-us/azure/backup/backup-mabs-install-azure-stack).

## Applicability

Apply this placement review to Microsoft Azure Backup Server on Azure Stack Hub. Validate the chosen operating system, MABS release and SQL combination against the current requirements; the installation page’s older sizing examples are not a general capacity recommendation.

## DSE recommendation

Reject a shared remote-database design before starting installation. Document the backup server’s purpose, its local database dependency and the proposed cohosted roles. Have the infrastructure owner approve an eligible dedicated machine and the database-maintenance responsibility. Keep the placement decision separate from the organization’s ordinary SQL consolidation policy. Do not move an existing installation or remove another workload merely to make the proposed diagram fit; plan any migration as a separately supported change.

## Verification

Review the proposed machine’s installed roles and the actual location of the selected SQL instance. During an approved installation rehearsal, retain prerequisite-check results and confirm that the backup service uses the intended local database. Resolve a placement mismatch before scheduling protected workloads. Record capacity assumptions for later measurement instead of copying the source’s historical virtual-machine examples into an operational guarantee.

## Official references

[Microsoft Learn: Install Azure Backup Server on Azure Stack Hub](https://learn.microsoft.com/en-us/azure/backup/backup-mabs-install-azure-stack).

## Primary reference

- Name: Install Azure Backup Server on Azure Stack Hub - Azure Backup | Microsoft Learn
- Authority: Microsoft Learn
- URL: https://learn.microsoft.com/en-us/azure/backup/backup-mabs-install-azure-stack
- Source publication date: Not stated by the source

## Citation and use

Preferred citation: “Keep the MABS SQL instance local when planning an Azure Stack Hub installation,” DSE Security, https://update.dsesecurity.com/updates/dse-20260909-527-keep-the-mabs-sql-instance-local-when-planning-an-azure-stack-hub-installation/
Publishing principles: https://update.dsesecurity.com/updates/dse-updates-editorial-methodology/
Usage and citation policy: https://update.dsesecurity.com/usage/
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