What Is ReFS File System? Everything You Need to Know

Jean updated on Feb 22, 2023 | Home > Knowledge Center

What is ReFS File System

Resilient File System (ReFS) is an advanced file system launched by Microsoft, which was launched with Windows Server 2012 in September 2012. In the early days, ReFS could only be used to store data, but now it can boot the system and also be used on mobile hard disks.

ReFS is composed of NTFS (New Technology File System) file system code, which also implies Microsoft's purpose in designing ReFS. Microsoft hopes that ReFS can become a new generation of the file system, with maximum data availability, meet greater data storage requirements and workloads, and solve the problems of the NTFS file system.

choose refs file system

ReFS was initially only used in Windows Server 2012. In October 2013, Microsoft began to add ReFS to the desktop version of Windows 8.1. In the update of 2017, except for Windows 10 Pro for Workstation, the function of creating ReFS volumes in Windows 10 was removed. However, the operating system can still read ReFS volumes.

How ReFS File System Works

Microsoft not only uses the NTFS code base to design the ReFS file system but also adds support for Win32 APIs to provide compatibility with existing APIs to support ReFS with more features.

The ReFS file system uses the B+tree structure to manage data through metadata indexing and maintains high compatibility with NTFS. The B+tree structure can support ReFS to store more data using the branch mode and reduce disk I/O to improve performance. On the basis of NTFS, ReFS can maintain higher consistency and data integrity, thus enabling data recovery in case of system errors.

b+ tree structure

Main Functions of ReFS

As a new-generation file system after NTFS, ReFS has three new functions: Disk Construction Reliability, Build-in Resilience, and Mirror-accelerated Parity.

Disk Construction Reliability

Because the ReFS file system uses the B+tree structure, it can support a large amount of data. Currently, ReFS supports a maximum file size of 16 EB and a maximum volume size of 35 PB.

Build-in Resilience

Without using Check Disk(CHKDSK), ReSF can check files and repair file corruption when users read or write files. In addition, the data integrity scanner will regularly check and repair all files on the drive, which means ReFS has internal flexibility to check whether the file data is damaged, and provides higher integrity and availability for the data.

Mirror-accelerated Parity

The mirror accelerated parity function allocates data to two layers on the drive. The ReFS file system quickly writes data to the disk in the mirror layer and then transfers the data to the parity layer to recalculate each written file. This not only enables more efficient data storage but also makes more efficient use of disk space.

Pros and Cons

Although the ReFS file system is highly expected by Microsoft, it cannot be a real substitute for NTFS at present. ReFS has many functions that other file systems do not have, and it also has many shortcomings that need to be improved.

Pros Cons
  • Enhanced ability
  • Extremely fast processing speed
  • Automatic data check
  • Strong scalability
  • Need not the support of CHKDSK
  • Some software does not support this file system
  • Cannot convert NTFS data to ReFS data
  • consumes more system resources


In short, ReFS is an advanced file system launched by Microsoft. With its unique functions, it can effectively help people access, write, modify and protect data easily. But although it has excellent performance, it is still not a perfect substitute for NTFS.

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Updated by Daisy

Daisy is the Senior editor of the writing team for EaseUS. She has been working in EaseUS for over ten years, starting from a technical writer to a team leader of the content group. As a professional author for over 10 years, she writes a lot to help people overcome their tech troubles.

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Written by Jean

Jean has been writing tech articles since she was graduated from university. She has been part of the EaseUS team for over 5 years. Her special focuses are data recovery, disk partitioning, data space optimization, data backup and Mac OS. By the way, she's an aviation fan!

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