Q: When should I use ReFS withand Windows Server 2012 R2?
A: Windows Server 2012 introduced ReFS as an additional file system option. It features improved resiliency and availability over NTFS. However, in Windows Server 2012 and Windows Server 2012 R2 it also lacks some capabilities, which means it's not an option for many workloads (including SQL Server, Hyper-V, and many file server roles). The question is often asked, what should I use ReFS for?
In Server 2012 and Server 2012 R2, it's actually fairly simple: Use ReFS for archived data. If you have critical data that needs to be archived and needs the highest levels of resiliency such as for huge image files, archived VHD files, or anything else important, then store it on ReFS.