Support matrix for backup with the Microsoft Azure Recovery Services (MARS) agent

You can use the Azure Backup service to back up on-premises machines and apps and to back up Azure virtual machines (VMs). This article summarizes support settings and limitations when you use the Microsoft Azure Recovery Services (MARS) agent to back up machines.

The MARS agent

Azure Backup uses the MARS agent to back up data from on-premises machines and Azure VMs to a backup Recovery Services vault in Azure. The MARS agent can:

  • Run on on-premises Windows machines so that they can back up directly to a backup Recovery Services vault in Azure.
  • Run on Windows VMs so that they can back up directly to a vault.
  • Run on Microsoft Azure Backup Server (MABS) or a System Center Data Protection Manager (DPM) server. In this scenario, machines and workloads back up to MABS or to the DPM server. The MARS agent then backs up this server to a vault in Azure.

Your backup options depend on where the agent is installed. For more information, see Azure Backup architecture using the MARS agent. For information about MABS and DPM backup architecture, see Back up to DPM or MABS. Also see requirements for the backup architecture.

Installation Details
Download the latest MARS agent You can download the latest version of the agent from the vault, or download it directly.
Install directly on a machine You can install the MARS agent directly on an on-premises Windows server or on a Windows VM that's running any of the supported operating systems.
Install on a backup server When you set up DPM or MABS to back up to Azure, you download and install the MARS agent on the server. You can install the agent on supported operating systems in the backup server support matrix.

Note

By default, Azure VMs that are enabled for backup have an Azure Backup extension installation. This extension backs up the entire VM. You can install and run the MARS agent on an Azure VM alongside the extension if you want to back up specific folders and files, rather than the complete VM. When you run the MARS agent on an Azure VM, it backs up files or folders that are in temporary storage on the VM. Backups fail if the files or folders are removed from the temporary storage or if the temporary storage is removed.

Cache folder support

When you use the MARS agent to back up data, the agent takes a snapshot of the data and stores it in a local cache folder before it sends the data to Azure. The cache (scratch) folder has several requirements:

Cache Details
Size Free space in the cache folder should be at least 5 to 10 percent of the overall size of your backup data.
Location The cache folder must be locally stored on the machine that's being backed up, and it must be online. The cache folder shouldn't be on a network share, on removable media, or on an offline volume.
Folder The cache folder should be encrypted on a deduplicated volume or in a folder that's compressed, that's sparse, or that has a reparse point.
Location changes You can change the cache location by stopping the backup engine (net stop bengine) and copying the cache folder to a new drive. (Ensure the new drive has sufficient space.) Then update two registry entries under HKLM\SOFTWARE\Microsoft\Windows Azure Backup (Config/ScratchLocation and Config/CloudBackupProvider/ScratchLocation) to the new location and restart the engine.

Networking and access support

URL access

The MARS agent needs access to these URLs:

Throttling support

Feature Details
Bandwidth control Supported. In the MARS agent, use Change Properties to adjust bandwidth.
Network throttling Not available for backed-up machines that run Windows Server 2008 R2, Windows Server 2008 SP2, or Windows 7.

Support for direct backups

You can use the MARS agent to back up directly to Azure on some operating systems that run on on-premises machines and Azure VMs. The operating systems must be 64 bit and should be running the latest services packs and updates. The following table summarizes these operating systems:

Operating system Files/folders System state Software/Module requirements
Windows 10 (Enterprise, Pro, Home) Yes No Check the corresponding server version for software/module requirements
Windows 8.1 (Enterprise, Pro) Yes No Check the corresponding server version for software/module requirements
Windows 8 (Enterprise, Pro) Yes No Check the corresponding server version for software/module requirements
Windows 7 (Ultimate, Enterprise, Pro, Home Premium/Basic, Starter) Yes No Check the corresponding server version for software/module requirements
Windows Server 2016 (Standard, Datacenter, Essentials) Yes Yes - .NET 4.5
- Windows PowerShell
- Latest Compatible Microsoft VC++ Redistributable
- Microsoft Management Console (MMC) 3.0
Windows Server 2012 R2 (Standard, Datacenter, Foundation, Essentials) Yes Yes - .NET 4.5
- Windows PowerShell
- Latest Compatible Microsoft VC++ Redistributable
- Microsoft Management Console (MMC) 3.0
Windows Server 2012 (Standard, Datacenter, Foundation) Yes Yes - .NET 4.5
- Windows PowerShell
- Latest Compatible Microsoft VC++ Redistributable
- Microsoft Management Console (MMC) 3.0
- Deployment Image Servicing and Management (DISM.exe)
Windows Server 2008 R2 (Standard, Enterprise, Datacenter, Foundation) Yes Yes - .NET 3.5 , .Net 4.5
- Windows PowerShell
- Compatible Microsoft VC++ Redistributable
- Microsoft Management Console (MMC) 3.0
- Deployment Image Servicing and Management (DISM.exe)
Windows Server 2008 SP2 (Standard, Datacenter, Foundation) Yes No - .NET 3.5 , .Net 4.5
- Windows PowerShell
- Compatible Microsoft VC++ Redistributable
- Microsoft Management Console (MMC) 3.0
- Deployment Image Servicing and Management (DISM.exe)
- Virtual Server 2005 base + KB KB948515
Windows Storage Server 2016/2012 R2/2012 (Standard, Workgroup) Yes No - .NET 4.5
- Windows PowerShell
- Latest Compatible Microsoft VC++ Redistributable
- Microsoft Management Console (MMC) 3.0
Windows Server 2019 (Standard, Datacenter, Essentials) Yes Yes - .NET 4.5
- Windows PowerShell
- Latest Compatible Microsoft VC++ Redistributable
- Microsoft Management Console (MMC) 3.0

For more information, see Supported MABS and DPM operating systems.

Backup limits

Azure Backup limits the size of a file or folder data source that can be backed up. The items that you back up from a single volume can't exceed the sizes summarized in this table:

Operating system Size limit
Windows Server 2012 or later 54,400 GB
Windows Server 2008 R2 SP1 1,700 GB
Windows Server 2008 SP2 1,700 GB
Windows 8 or later 54,400 GB
Windows 7 1,700 GB

Supported file types for backup

Type Support
Encrypted Supported.
Compressed Supported.
Sparse Supported.
Compressed and sparse Supported.
Hard links Not supported. Skipped.
Reparse point Not supported. Skipped.
Encrypted and sparse Not supported. Skipped.
Compressed stream Not supported. Skipped.
Sparse stream Not supported. Skipped.
OneDrive (synced files are sparse streams) Not supported.

Supported drives or volumes for backup

Drive/volume Support Details
Read-only volumes Not supported Volume Copy Shadow Service (VSS) works only if the volume is writable.
Offline volumes Not supported VSS works only if the volume is online.
Network share Not supported The volume must be local on the server.
BitLocker-protected volumes Not supported The volume must be unlocked before the backup starts.
File system identification Not supported Only NTFS is supported.
Removable media Not supported All backup item sources must have a fixed status.
Deduplicated drives Supported Azure Backup converts deduplicated data to normal data. It optimizes, encrypts, stores, and sends the data to the vault.

Support for initial offline backup

Azure Backup supports offline seeding to transfer initial backup data to Azure by using disks. This support is helpful if your initial backup is likely to be in the size range of terabytes (TBs). Offline backup is supported for:

  • Direct backup of files and folders on on-premises machines that are running the MARS agent.
  • Backup of workloads and files from a DPM server or MABS.

Offline backup can't be used for system state files.

Support for data restoration

By using the Instant Restore feature of Azure Backup, you can restore data before it's copied to the vault. The machine you're backing up must be running .NET Framework 4.5.2 or higher.

Backups can't be restored to a target machine that's running an earlier version of the operating system. For example, a backup taken from a computer that's running Windows 7 can be restored on Windows 8 or later. But a backup taken from a computer that's running Windows 8 can't be restored on a computer that's running Windows 7.

Next steps