SOLVED: Easily Move the MABS Scratch Disk Folder Location

If you want to backup an on-prem server to Azure, the easiest way to do it is with Microsoft Azure Backup Server (aka MABS). To do this your server needs free space of about 8% (Microsoft says 5%-10%) of the space you are backing up. So if you want to backup 1TB, you should have AT LEAST 80GB free.

Here is the catch. Is you are also backing up the System State of a Domain Controller, your server needs and ADDITIONAL 35GB. Sooo, in our example with a server that has 1TB of data, if it was also a DC, your server requires AT LEAST 115GB (80GB + 35GB) of free space to operate MABS. That is the amount of SCRATCH space MABS needs.

That default location of the MABS scratch folder is c:\Program Files\Microsoft Azure Recovery Services Agent\Scratch . So you may have disk space limitations on your C:\ and need to move MABS scratch folder after the initial installation.

Does MABS Scratch Folder Support All Disk Features?

MABS cache / scratch folder has to be located on a normal NTFS or ReFS disk so none of these features are supported:

• Compressed
• De-duplicated
• Encrypted
• Sparse
• Reparse-Point

How To Change the MABS Scratch Disk Folder Location:

1. In SERVICES
   • stop the MICROSOFT AZURE RECOVERY SERVICES AGENT
   • stop the MICROSOFT AZURE RECOVERY SERVICES MANAGEMENT
2. Copy the all of the files and folders from the current, to the new SCRATCH folder, except the
3. In the REGISTRY
   • Change HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Azure Backup\Config\ScratchLocation to point to the new scratch folder
   • Change HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Azure Backup\Config\CloudBackupProvider\ScratchLocation to point to the new scratch folder
4. In Services
   • start the MICROSOFT AZURE RECOVERY SERVICES AGENT
   • start the MICROSOFT AZURE RECOVERY SERVICES MANAGEMENT

Now you should run a test backup to make sure all is well.