Windows Server 2016 stops responding during synthetic operations on a ReFS repository

Challenge

Windows Server 2016 stops responding during the disk activity that involves block cloning for the Resilient File System (ReFS). That may happen, for example, when applying retention or creating a synthetic full backup.

Cause

This is the limitation of ReFS on Windows Server 2016 confirmed by Microsoft Support.

Solution

Install Windows Server 2019 with KB4534321 that improves the performance of block cloning for ReFS in scenarios that involve a large number of operations on ReFS-cloned files.