ReFS Best Practices

Microsoft Resilient File System (ReFS) version compatibility has an important impact on mounting your backed up images and on accessing and restoring your data that is saved on ReFS formatted volumes. This page describes the information you need to know to avoid compatibility problems. When you backup systems that use ReFS-formatted volumes, keep these operating system compatibility requirements in mind.

ReFS Version Compatibility - Different versions of Windows Server come with slightly different versions of ReFS and they don't all work the same way.

ReFS is forward-compatible but not backward-compatible. In other words, you can access volumes formatted with newer versions of ReFS by the same version or newer versions of Windows, but not the other way around. Older versions of Windows cannot read or mount ReFS volumes created on newer operating systems.

If you attempt to mount an SPX backup image on Windows Server 2016 or 2019 that was created with a newer Windows Server version such as Windows Server 2022, it will probably fail because the older operating system does not support the newer version of ReFS.

Best Practice things to remember - Successfully mounting and accessing backup images with ReFS volumes require you to mount those images on the same version of Windows Server they were created with, OR a newer supported Windows Server version.

Supported Example - If you created a backup image from an ReFS volume on Windows Server 2022, you should only attempt to mount that image on Windows Server 2022 or a newer version of Windows server.

Not Supported Example - If you created a backup image from an ReFS volume on Windows Server 2022 and attempt to restore it to an older version of Windows such as Server 2016 or Server 2019 the mounting may (is likely to) fail.

Also see Release Notes Enhancements for additional version information.