After fourteen years of waiting, Microsoft is introducing boot support for the Resilient File System (ReFS) in Windows Server. Insiders can now boot the server OS directly from a ReFS volume, a first since the file system was launched in 2012.
The ReFS file system was launched in 2012 with Windows Server 2012, but until now lacked the ability to boot directly from it. The latest Windows Server Insider Preview build addresses that shortcoming. Organizations can now install and boot the server operating system from a ReFS volume, something that has been possible with NTFS for decades.
As Windows Server 2016 approaches the end of support, the change may be of interest to upgraders who want to build a more secure server environment. For organizations migrating to newer versions, ReFS boot now offers an alternative to the long-standing NTFS monopoly.
Advantages over NTFS
Microsoft promises significant improvements over NTFS with ReFS boot. The file system detects corruption at an early stage and handles problems online, without the need for chkdsk. This focus on data integrity makes ReFS particularly suitable for critical environments.
In addition, the integrity-first design reduces the risk of corruption due to crashes. While NTFS systems already support large volumes, ReFS goes one step further with support for volumes up to 35 petabytes. That’s 35,000 terabytes, enough to rule out capacity problems for years to come.
Finally, ReFS uses block cloning and sparse provisioning. These technologies enable enterprises to easily create and expand large fixed-size VHD(X) files. They also significantly speed up the copying of large files.
Long road to boot support
Since its introduction in 2012, Microsoft has gradually expanded ReFS. In 2013, an update followed with better performance, tiered storage, and faster metadata operations. Windows Server 2016 brought block cloning for VMs and databases, sparse VDL for faster virtual disk creation, and improved Hyper-V integration. With Windows Server 2019 and 2022, Microsoft further improved performance, as well as repair and integrity capabilities.
Organizations that want to test ReFS boot now should install the recent Windows Server vNext Insider Preview. Builds from February 11, 2026 (minimum build number 29531.1000.260206-1841) include ReFS boot in the setup.
During the installation process, users format the system partition (C:) as ReFS via the installation UI. Microsoft emphasizes that ReFS boot requires UEFI firmware and does not support legacy BIOS boot. After installation, administrators check the file system via the properties of the C drive.